Can you post a pic?
The etcher marked Ruana's with the "bullwhip" underneath the sig. were used through out the years.
Somtimes, you see them with the M stamped into the guard, other times not.
The current marks are:
Ruana
Bonner
Montana
Ruana (Script).
V.H. Ruana (Script).
_______
The Older Knives:
(early 40's-64).
R.H. Ruana
Bonner
Montana-- baby bowie stamp.
(64-till about 83).
R.H. Ruana
Bonner
Montana- M.
R.H. Ruana
Bonner
Montana- M(sometimes not).
Script sig. w. Bullwhip.
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This doesn't include various test stamps and the knives done with his son Dave. How is the handle pinned? More pins usually means older knife.
The dove-tailed scales are used on later knives, square cut ones are a bit earlier.
There's a book called
Hear The Hammer , that is a great book on the subject. I'd look through it, but I misplaced it.
Ruana(
www.ruanaknives.com ) can date the knife, if you send them pics/info.
I think your knife is a close to retirement knife, as the signature was used mostly on those, but he did use it sporadically through-out his career. I need a pic.
HTH

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