Sidemount locks

[Dave Henderson]

On what make(s) and year(s) were these sidemount locks used?   My assumption is that they worked on either side, however both are identical so I could be wrong, comment?   A Briggs and Stratton key fits.  I have examined these closely to ascertain a method to remove their cylinders, but find no pin or other retaining device, any ideas?  

[drwatson]

My B+S catalog goes back to 1929. A good view of the key front & back might provide a clue (for make & year).  

[Dave Henderson]

drwatson,
Thanks for the offer to help.  The key I used is an aluminum GM key that I just happened to have,  I'm sure it is newer than the locks.  It was the third key I tried and a lucky coincidence that it worked on one of the locks.  I used lock ease and tried about 50 other keys that fit into the other lock, but none worked.  The cylinders are not stuck.  
Usually there is a way to remove cylinders, sometimes requiring that a correct key be used in the process or by drilling out a pin, but so far I haven't come up with a method for these. 
I D and Ideas needed!

[roysboystoys]

Maybe a photo of the inside lock mechanism would help?

Most likely a retainer on the Plunger or lock piece has to be removed

[drwatson]

I see your lock pictured at this web site. They say "GM".

http://exwisehe.com/accessory_locks_tire_8.html

[Dave Henderson]

Thanks guys.  The view pictured shows the plunger to be plain and blunt ended, and it will not pull farther out.   Nothing else worthy of suspicion except there is a coil spring farther in the bore that I will try to remove to see if anything is beneath it.  I chalked over the bottom to show up a logo, 2 diamonds standing up, over an "H".
Identifying the locks as GM is a big help.  The accessory lock web site is the best I have ever seen.