Best left to a gunsmith
A Westernfield M72 (actually a M72C) is a Mossberg Model 472. You might try http://www.krausebooks.com/category/firearms_knives for disassembly instructions for the Mossberg 472 in the Gun Digest Sporting Rifle Assembly/Disassembly book.
I recently bought a mossberg 472 30-30 for 285.00
The western field (montgomery wards) model 72C was made by mossberg arms company.The mossberg model 472 is the same as a western field model 72C.
Marlin made the 336 for Western Auto Revelation 103.450 & .451. mossberg also made their model 472 lever gun for Western Auto Revelation 205.
100-340 or so
Do not attempt to use other than a Mossberg bolt made for that rifle.
You have not asked a question. Yes, the lever action 472 was a 30-30 rifle, similar in many ways to the Marlin 336, made in the 1970s for a few years- at least 3 different models, value, based on condition, may range from $150-$250.
A Mossberg 22 rifle such as the Plinkster depending on the condition is worth around $150-200.
50-150 or so
It is the rifling in a mossberg rifle barrel.
There are dozens of different models of the Mossberg 22 rifle. You did not tell us which model, and we need that to give you an answer. Sorry.
Your rifle was made for Montgomery Ward stores by Mossberg, and is a Mossberg 346K. You can check with a gunsmith, or check the website for gunpartscorp (look under Mossberg). Havlinsales also stocks many Mossberg parts.