What you have is an old action.

Pic #1
The notch ( keyway) in the old bothead aligns with a key in the bolt body. They were used to prevent installing the bolthead 180 out. (upside down). The newer boltheads-bodies do not have them. To use that bolthead either the shaft would need to have the notch cut in or the key in the bolt body removed.

Pic #2-3
The pin in the bolthead and the notch in the baffle were used to stop the bolt rotation when opened.

Another difference you'll find is the firing pin diameters. Your old pin will be .140". Newer pins are .095". The firing pin and bolthead retaining pin would need to be changed to the .095" or the bolthead shaft opened to accept the old pin diameter.

I have an old "Westpoint 410" exactly like your rifle with the exception it doesn't have the bolt guide on the baffle. Instead of going to all the trouble making,modifying and changing parts I stuck a new 30-06 barrel on it, stuffed it in a designer gray 200 stock and keep it around for a loaner rifle.

Bill