A shot in the dark, but why not : I have a .38 Spl HD that lettered to 1930 shipping date to Portland, OR and Marshall Wells . It has since been customized including engraving - I have no history on it other than the factory letter.
The aftermarket engraving is decent and a flower motif that matches the backelite grips . Picture being attached, sn : 359XX . In the photo you will see a set of initials engraved into the right crane area - they are I believe "AIA" . Anyone have any info or comment on how I might find the engraver , and or more info on this gun.