Thanks Leon!
OK so the tally is now at two complete sets, one with mixed backs and one all HLC backs...
Nice! that gives me hope and my quest continues now with renewed enthusiasm!
I suspect since the HLC complete set owner won't post, that he wont share some pictures...
So for what its worth... Burdick found a nice one, currently residing in his collection at the Met. Unfortunately they have not identified the manufacturer on the back, maybe if a board member makes a trip to see the collection they can try and see what back it is...
here is a pic and the link:
Bruce Brown - Miners extra.jpg
https://www.metmuseum.org/art/collection/search/694928
TTYL!
Cliff