Thanks guys.
A little more from my buddy this morning, but not much.
He doesn't know much about Grandpa beyond that he was Canadian.
Grandpa died when my buddy was 16 or 17, he did know him, but nothing about his military background beyond what he remembers concerning mention of the gun and the trenches in that long-lost diary. He was able to grab & stash the gun after the death because he knew his mother would get rid of it.
He's not in good health now, his two daughters have no interest in the gun, and he'd like to see it get into the hands of somebody who'd appreciate what it is.
He confirms the serial at 124X.
Looks like that last of what I thought was five digits in the blurry photo is a crown.
I can't tell in the photo, he says it's 124X followed by a crown.
If the gun were mine, I'd give you the entire number, but it's not, so some privacy there.
Asking him to check more carefully for other proofs, like NP, sword/arm, anything else.
Inferring from the diary remark about the Germans & Canadian trenches, assuming Grandpa was with a Canadian Army unit.
Did the CA get any of the 1st Models?