Variations of S&W M-100

I just bought a pair of early Smith & Wesson Model 100 handcuffs.





These are marked "PAT'S PENDING" and do not have the model number stamped on them.

They are made in Springfield, Mass.

They do have the double lock slots through both side plates like later M-100s, unlike examples I've seen in collections that had the slot only on the keyhole side.


Now I see a set on eBay that are identical to these but are made in Houlton, ME.


In my collection so far I have three distinct variants of the nickel M-100:

The aforementioned "PAT'S PENDING" set made in Springfield, Mass.

A set with the old-style elongated 'dimple' made in Houlton, ME.

A current product set with the round 'dimple' made in Houlton, ME.



Just how many distinct variations of the Model 100 are there?

I suspect there are many as they changed things, I had a pair that said Springfield, Ma and had rivets that were raised, not the weled pins they use now...