Probably not owners marks, there is a related pair, in the collection of the Davistown Museum, 2 stamped the same makes it lean towards makers mark....
from the site:
"42801T6 Dividers
Cast steel, signed "S H F Bingham Cast Steel".
No SHF Bingham is listed in DATM (Nelson 1999) or in Cope's (1993) American Machinists' Tools; probably a heretofore
unrecorded American toolmaker. Was there an English manufacturer with this name?"