Mitchell,
Yep, I am familiar with the temporary steel snaps.  The one I posted has a Heiser snap on the keeper that is of "baby dot" construction.  Joe said he has never seen a baby dot type snap on a Heiser/Randall sheath, so I thought he would find it interesting.
 
I have seen (in hand, not photos) more sheaths than I can count, some with Heiser on the snap, but I have to say, that most that I recall were of the glove type. Not saying I didn't have any of the baby dot type in my hands, just never put any weight into it. I don't believe any of the Heiser marked snaps were beyond the mid 50's though. 
Obviously there are a few examples out there, apparently very few, well one maybe, but there nonetheless. 
Funny thing is though, 
keepers are set at RMK. Maybe RMK had a few Heiser buttons around the shop? Hmmmm. 
I think Rod's sheath definitley has a replacement keeper and it appears to be a smaller snap than on the model 2.