It appears to be a Model 36-1, the 3” heavy-barrel variant of the Chiefs Special.

The serial on the side of the topstrap is non-standard. The triple-alpha serials are a bit confusing, but based on available data in the Standard Catalog the AHF should fall into 1985, which fits your timeframe.

The catalog appears to contain no reference to this special order. Contacting Roy Jinks might indeed be your best bet.