What I know:
The dual shaped keyhole was Fraim’s way to master key a padlock, the straight leg would’ve been for the master key and the other shape was for the “change” or individual user key. This shape would be different depending on what the lock was used on. For example in a large industrial setting the shed’s individual key would be shaped like a dogleg curved to the left wheras the front gate padlock might be shaped like a number “9”, the rear gate might be also shaped like a number “9” but it’s respective key will enter but not turn in the front due to different wardings or cutouts in the key. The master key would have all positions cut away in order for it to bypass all the different wards in multiple locks it should operate. Both keys would have resembled a “railroad key” of the era. The number on the shackle would be a code corresponding to both the shape of the individual key as well as what the cuts on the blade are to be, I am into a several year long project of analyzing the numbers on master keyed padlocks made by Fraim in order to decode their methology of what the codes meant. Your’s is the first I’ve seen that the (master) straight cut is on the right as opposed to being located on the left. The Fraim keystone logo and date being on the front of the shackle instead of the back posed one of two things: either the locks were ordered UNMARKED from the factory as Fraim would mark (stamp) the front with the customer’s name or other info when requested and then put their own logo and date on the backside of the shackle… OR it means the customer’s name or initials were originally cast or embossed onto the rear vertical panel you call the “back strip” and someone ground them away later on. This was common practice for someone (back in the day) to steal an employer’s lock and deface the logo or identifying marks in order to use the padlock personally. It was also a common thing for the owner of the lock to deface their own name or marks when disposing of said padlocks in an attempt to foil someone wishing to de-engineer the lock, make a top level master key from it, and gain access to whatever the other locks may be securing. This practice was especially used in institutions of high security such as prisons or universities and places of great technology & innovation like Bell Labs and NASA. Your lock seems to have striations on the rear panel indicitive of grinding, I can’t say with utmost certainty why though. The other companies known for this style of master keying were Eagle Lock Co of Terryville, CT USA, and Safe Padlock Co. also of Lancaster, PA USA. Both because of the master keying and the chain attachment point on the bottom of the case I would confidently believe it was used in a fairly large industrial setting like a railroad, huge industrial complex like a paper mill, warehouse or even a prison and not on somebody’s chicken coop!
Hope this helps some,
–Vince
PS, There is a large lock collectors show in Lancaster this summer in case you are unaware: Google “Lancaster Lock Show” for info.
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