Transition lamps between adjacent models of Aladdin kerosene lamps are the norm.  Also when Plume & Atwood was manufacturing more than one version of Aladdin lamp at a time and ran out of parts for one, they used the corresponding part from the other line until additional parts came in, producing factory hybrids.   Aladdin was in business to make money and not to have "correct lamps" for future collectors.

Wherever possible the factory used or reworked stock on hand  to go on new lamps.  Throwing away perfectly good usable parts was throwing away money.  I suggest that collectors might wish to think twice about correcting  what they believe to be a hybrid between two adjacent models of Aladdin lamps.  That might just be the way that particular lamp shipped from the factory and you just might be destroying a piece of Aladdin history.

To further complicate things, Aladdin also sold lamp parts to dealers who might well have assembled lamps out of available parts in order to sell old model parts stock that might have otherwise sat on their shelves unsold.

In addition, Plume and Atwood, the company who made kerosene lamps for Aladdin, had their own schedule which often did not coincide with the Aladdin model years  Hence early and late versions of an Aladdin model were created when the P&A tooling changed during an Aladdin lamp model year. 

Tooling did not always wait until between model years to wear out or break.  So changes can be seen within a model that are the result of tooling changes.  The glass Aladdin lamp collectors see this all the time on lamp styles that were in production for several years.  Some styles went through several glass molds, each a little different.

Model 1-2 and Model 2-3 transitions:

The Aladdin model 2 lamp was officially in production for just 4 months and underwent a large number of changes.  For practical purposes one could consider the model 2 to be  a morphing transition between the model 1 and model 3 lamps.

Early model 2 lamps used reworked model 1 galleries with a brass ring inserted at the inside top of the gallery to block off the top ring of holes (Change needed for the #2 generator).

Part way through production the screw stop that limited wick adjustment travel  disappeared from the burner adjustment shaft.  Part of production used a 2 part concave air distributor and part used a one piece concave air distributor.

P&A changed the table font during the model run as well.  Later model 2 lamps have the threads hidden inside a raised collar and had strengthening radial groves at the bottom of the bowl.  Except for the thread pitch it looked like an early model 3 lamp base (Chime shape was different in late model 3).

The last model 2 lamps used model 3 generators and the model 3 KoneKap gallery with the international patent markings.  For all practical purposes this lamp was a model 3 that used the #2 burner, wick holder and a model 2 thread insert. A late model 2 or an early model 3?  I suspect these lamps were sold into the model 3 production timeframe until Aladdin ran out of #2 burners.  At this writing I own three model 2 table lamps and each one is different.

Very early model 3 burners had the long slots in the base cut the same as the model 1 & 2 slots. The common #3 burners have shorter slots the same as the model 4 and 5 burners.

Model 3 - 4 transition:

Early model 4 lamps are found with model 3 galleries indicating that there were still stocks of model 3 galleries on hand at the model change. The primary difference between model 3 and 4 is the generator and the labeling on the side of the gallery and wick adjustment knob.

Also note that Plume and Atwood replaced the generator seat forming tooling for the inner wick tube some time during model 4 production. The formed seats have a slightly different look depending upon which tool was used.

Model 8 - 9 Transition:

One would normally think that except for the outer wick tube, wick holder and wick riser nothing was carried over from the model 8 to the model 9 and you would be right.  Except there was excess stock of model 8 galleries that were nickel plated  and fitted to early model 9 lamps.

Second year model 9, model 10 and model 11 were all basically the same lamp with real minor changes likely brought about by replacement tooling.

Model 11 - 12 transition:

The lamp at the top of the page is an extreme example of a model 11 to 12 transition lamp and proof positive that the factory used up early model parts on hand whenever possible (even if a little implausible).

The big question is did the factory run out of model 11 burners before they ran out of model 11 fonts and ship model 12 burners on model 11 fonts. What confuses this answer is that Aladdin ran a major burner upgrade promotion when the model 12 was introduced.  The promotion was to get people to trade in their model 7 through 11 burners for model 12 burners.  The  likely reason for the promotion was to quickly build sales numbers on the new Lox-on mantles and chimneys. This in turn provided the retailers with more incentive to make space on their shelves for these new parts and made production lines profitable faster.

I personally am in the side that advocates that the factory ran out of #11 burners before they ran out of the fonts. There seems to be a much higher percentage of model late 9, 10 and 11 fonts  found with #12 burners than of model 7, 8 and early 9 fonts found with #12 burners.  I can not justify this by saying that people who recently purchased a lamp were more apt to trade in perfectly functional almost new burners than were people who had purchased their lamps a few years earlier.  It seems to me that people with old burners would be most likely to want to upgrade  and that there would be a higher proportion of model 7, 8 and early 9 fonts with model 12 burners than later fonts  if Aladdin did not sell a transition lamp that had model 11 fonts and #12 burners.

Models 12 and B burners were both in production from the time that the model B was introduced until a flood destroyed the tooling for both burners during the winter of 1953.   During that time if production of one burner ran out of stock, the corresponding part from the other model burner was used until additional parts arrived.