Help dating my Marbles Ideal

[jkw009]

Any thoughts on this? Thanks!

https://imgur.com/jdeSHig

https://imgur.com/vMaXRNP

[btrwtr]

It's not an Ideal it is a Marble's Expert. I don't believe the sheath is original Marble's. Not sure how old it is but that would have little to do with the value.

[jkw009]

Thanks. How can you tell it's an expert vs Ideal?

[btrwtr]

A Ideal would have a hollowed out fuller in the blade vs. the flat blade of an Expert. Older Experts with 6" blades, M.S.A. stamps, Cocobolo wood handles or stag butt caps are harder to find and generally worth more. Your 5" blade Expert looks to be in pretty good condition.