Gibson H4 Question

[Roccus]

I've been trying to get a sense of the relative scarcity of truss rod H4s. It appears they first showed up in the late '22's or possibly early '23s. Gruhn says they were continued until the late '20s but appeared in the catalogs until 1940. Spann, on the other hand, says they were produced until 1937 based on observed examples. The last one to appear in the archives has a shipping date of 1931 based on Spann's research. Does anyone have any more recent info that can pin down the production time span a little tighter. Thanks.

[mrmando]

Whatever the production time was, my impression is that there just weren't that many of them built.