Gibson's lapsteels evolved into many styles in a short period of time. In  a comparison, the cast aluminum 1935 - early1936 E150 was vastly different from the next style E(EH)150 made early 1936-mid 1937. The first model had a cast- aluminum body with wide 'shoulders, screenprint 'Gibson logo' with no ornamentation, 29 fret unbound ebony fingerboard, unbound black bobbin pickup, tone and volume knobs on either side and a closed oblong bridge with 2 and later 3 screws.

The second model had a single bound maple top with a screwed on back (12 screws) and slimmer shoulders, 'Gibson logo' pearl inlay with no ornamentation, bound 29 fret rosewood fingerboard, unbound black bobbin pickup, tone and volume knobs on either side and an oblong bridge held by 2 and later 3 screws. 

According to 'Gibson Electric Steel Guitars' by A.R. Duchossoir, 

'...the first electric outfit commercialized by Gibson did not appear in the 'New Models' flier dated 1st October 1935 dedicated to the Super 400 and the 'advanced' arch-tops. The first production outfits were delivered from mid-November, e.g. guitar #110 and amp #1010 shipped to Jenkins Music on 14th November, or guitar #119 and amp #1008 shipped to E.E. Forbes & Son on 15th November.' 

Looking at the above serial #118, this lapsteel was one of the first commercially shipped Gibson electrics. Joesph Spann consulted the original Gibson shipping ledgers and added, '#118 was shipped on 9 December 1935 to Mr. H.M. Wirsing (a teacher/dealer in Flint, Michigan, 'A.R. Duchossoir') along with amplifier #1212.'   

1935 - early 1936 metal body with 'Gibson' logo silkscreened on headstock. Early 1936 - mid 1937 'Gibson' logo pearl inlay in headstock only. Mid 1937 - early 1938 'Gibson' logo pearl inlay as well as split-diamond pearl inlay in headstock.