Not economically feasible.
Ask a gunsmith for help
Do not attempt to use other than a Mossberg bolt made for that rifle.
The Mannlicher-Carcano has a six round internal magazine.
A Mossberg 22 rifle such as the Plinkster depending on the condition is worth around $150-200.
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.
Your westernfield model 732 rifle was made by mossberg as the mossberg model 810AH,for montgomery wards(westernfield).
S-130 is a type of rear sight used on Mossberg rifles- but not the model of the rifle. Take a look on the barrel.
Mossberg IIRC
Mossberg
50-100 usd