Just for some reference to what Skeleton Key look like and some of the uses.
In the bottom row these types of keys would have been used for doors and gates and such...
Longer shafts to reach through the doors.
The middle row keys were used mostly for cabinets, drawers and such...
Shorter shafts to reach through the lighter wood of a cabinet or drawer.
On the top row...
The left four keys were for padlocks. Which I feel yours is.
The short shank to the ridge on the shaft and beefy shanks show they were for a shallow lock only had to go through the metal side.
The next keys in the top row are clock winders and the last smallest key on the right is a watch winder.
Most of the clock and watch winders have round shafts with square center holes and some have a square end to grip the spring shaft.
With out a lock of some sort it is just a guess as to what old keys went to.
I'm sure you have a few modern tumbler keys lying around that you don't know what they went to.
Dating your key..
Best guess is with other finds that were in the same area and depth.
I would put it in the early 1900's
hope this helps
HH
