Tall Lincoln drape lamps were sold for 10 years. They have been found in clear, Alacite, cobalt blue and ruby red. Only a very small number of clear lamps were ever made and they may never have gone into the normal sales channels. The alacite lamp on the other hand was Aladdin's best selling lamp almost every year of production. The cobalt blue lamp was only made for the 1940 Lamp selling season.  Most of these very likely had the scallop foot design.  The ruby red lamp was only made during the 1941 lamp selling season and was likely halted because wartime restricted metal was used to make the colour.

Over the years several molds were used to make the lamps and there was often a lot of variation among the molds. It is believed that the first mold used in to make the Tall Lincoln Drape lamp was the scallop foot mold. Subsequent molds did not carry the scallop pattern. The rarity of the scallop foot makes it sought after by collectors.

The Alacite, blue and red lamps came with brass burners. Only the last year of production came with Nashville burners.

The tall lincoln drape lamp has been reproduced for several years and there are more reproduction red and cobalt tall Lincoln drape lamps than Aladdin ever made. Reproductions have been seen in clear, red, blue and amber (Aladdin never made any in amber). a very small number of alacite like reproductions were made in the 1980's 

There are numerous variations in foot pattern and height. It would be difficult to tell a reproduction just on the foot pattern alone. The best diagnostic I know of is the filler cap. Original lamps have a greater angle than reproductions and the bowl top surface is ramped up to meet the angled filler. When I collected tall Lincoln drape lamps I kept a real one and a reproduction side by side on display as a continual reminder of the differences.

These pictures show the scalloped pattern on the base of the scallop foot lamp. Alacite and blue lamps were made from the scallop mold. There are no red scallop foot lamps known to have been made.  The timing suggests that the scallop foot mold was the first of the tall Lincoln drape molds used.  This would indicate the scallop drape lamps were made during the 1940 lamp season, one year before the red Lincoln drape lamps were introduced.

Reproduction lamp.  Notice angle of filler

Original lamp.  Notice angle of filler

The clear, ruby and cobalt lamps have been reproduced  for some time and a number of different molds have been used to make the reproductions as well as the Aladdin originals.  This means there are a lot of variations in each.  So far the scallop foot version has not been reproduced.

The single best feature I have found to tell an original from a reproduction is the tilt of the filler cap.   Every reproduction I have seen to date has a level filler or just a slight tilt. The original filler cap sits at a very distinct angle.

Bill Courter's Aladdin book and his price guides have detailed descriptions of various reproductions and provides the best information on how to tell them apart. Assume clear lamps are reproductions, and that red and blue lamps are very likely to be reproductions unless a thorough inspection proves otherwise.