Ken,

You and I are on the same trek. Collecting all of them will be an adventure. I am trying to disassemble them to document the mechanisms.

Of just the Hammerless Sideplated Boxlocks(HLsplBL):
Lefever
Colton, Toledo OH - at least 2 models
Union FA Co, Toledo - at least 2 models
H&A - 2 models
Iver Johnson
W.H. Davenport.

Any others?

John