Looking for replacement Model 99 (.300) bolt

[Barneyhunts]

Thank you guys, I like what I'm hearing. It looks like I'm missing the little plate and screw meant to retain the lever, so I may have to hit up Ebay still. Now my question is how I tell if these assemblies have the firing pin mechanisms in them. I think when I took the breech out originally I took it out whole sale. I can post pics later to make it clear what I mean.
Also, how do I tell which model (like 99X)? The serial listing here says it was made in 1953.

I'd call Numrich and ask about the firing pin. The link you shared has a listing at the bottom for the bolt stop plate. I've bought parts for my 99 from them and they were as advertised.