Gibson Early 1937 EH150

Early 1937 EH150 FON 1238-20 next to a 2nd generation EH150 amp serial #4110.
Late 1936 left and early 1937 right. Both models feature no headstock ornamentation but have almost identical characteristics.
Optional hand rest made available in 1937.
Late-'36 lft and early-'37 right. Note the early '37 has a bound back, but only single bound. Mid-1937 models had a triple bound back and according to most reading, early-'36 to mid-'37's had no binding on the back.
Back of a triple-bound mid-1937 EH150.

It is commonly known that the transition of the EH150 model goes from the 1935 aluminum version to the early prototypic E150 of 1936, to the non-ornamentation with screwed on back of mid-'36-mid-'37  to the mid-'37-1938 model with headstock ornamentation, triple bound top/bottom and screwed on back. After 1938 the model has a glued on back with the newer horseshoe pickup inside.

The example featured on this page is unique as it only has 1-ply of binding on the screwed on bottom. The rest of this piece is consistent with the mid-'36-mid-'37 model.  

Both EH-150 and EH-150 amp set(both pictured on this page) were shipped June 17, 1937. (shipping ledger courtesy Lynn Wheelwright)
EH-150 pictured was sent to the factory for repair and reshipped from the factory with new single back binding circa July 1938. (shipping ledger courtesy Lynn Wheelwright).

There is apparently a bit more to the history of the EH-150 on this page. According to Lynn Wheelwright, this EH, #1238-20 is from a batch that began shipping 4-13-37. This one was one of the last two from this batch and shipped 6-22-37. #1238-2(the very last EH-150 from this batch) shipped 6-22-37, as well and has no back binding. 

Mr. Wheelwright goes on to explain that the next two batch's, batch 1239 with 25 units and batch 1319 with 50 units had no back binding. Batch 95 had 2 custom white Smeck sets with black top is 95-2. Most importantly, it is pointed out that batch 227 appears to be a trans batch where the bound backs start. There appears to only be triple and not single bound backs in this batch(like the photo above). 

This EH 150, #1238-20 was sent back to Gibson for some sort of repair in mid-1938 (the red mark means a re-ship following a repair). According to Mr. Wheelwright, 'the repair may have been the back had split and Gibson replaced it as by then they were shipping the glue back models.' 'This might be the only EH-150 with a factory original single bound back, albeit most likely a replacement.'

Note the shipping ledgers above. (courtesy Lynn Wheelwright)

Back of the single bound early 1937 EH150.
Shipping ledger courtesy Lynn Wheelwright.
Both models are identical in features and consistent with mid-'36 to the mid-'37 design. The single bound back is inconsistent with the documented triple bound back of the evolving mid-'37 specs.
Close-up of the single-bound back. A Gibson factory job performed in mid-1938 on this mid-1937 EH-150.
1-ply single binding around the back panel. A nice example of a transition into the mid-1937 model with the triple back binding and headstock ornamentation.
Almost identical to the '36 versions with the knobs on either end, 3 screws in the bridge and non-bound bobbin.
Very clean on the inside. Clean lines of the single binding.
FON 1238-20 stamped on the inside shoulder block.
Close-up of #1238-20. Barely visible and almost removed from a refinish.
Optional hand-rest which was an option made available later in 1937.
Pearl Gibson logo and no ornamentation present.