All I know is that around 1985 Tommy Armour, the company, came from a name change to Burke (also licenced the PGA branded clubs). For clarity I am posting this as a separte page but understand the PGA and Burke brands are the same company before 1985.
Clubs like the Tommy Armour 845s have small variations through the years. One easy to find example is the "pat pending" vs the "patented" versions of these clubs. At this writing I am not convinced there is a huge value difference but just be aware the "pat pending" version obviously predate the "patented" versions.