Regarding the “try out keys”, the ring of about 60 keys referenced several times above. I lucked out some years ago with a local locksmith that had a set and was able to help me with a lock on my ‘37.
I suggest letting your fingers do the walking through the yellow pages and try calling local lock smiths and asking if they can help or if they might know of someone locally, another locksmith likely, that might have a set. My guess is within five or so contacts or contact with a recommended contact someone locally will have a set. I am sure these sets were a common tool of the trade and recognized as such and passed along to another tradesman. That’s how I found the guy that helped me.
Good luck!
