Remove the stock and you will see what is keeping the bolt from sliding out.
Yes it is
Lift the bolt handle, pull the bolt to the rear. Depress the trigger and hold it to the rear and you will be able to remove the bolt. Unscrew the takedown screw (large screw visible on the bottom of the stock) and you will be able to separate the stock and barrelled action. That's as far as you need to go. sales@countrygunsmith.net
Try Browning or MGW
The Stock may be made out of wood or plastic. The Lock, Bolt, Barrel, and Trigger are all made of steel, or aluminum.
Not easily or readily.
Depends on the exact model, and condition. Anywhere from $300 to $2000. We need more information to give you an answer with any real meaning. Sorry-
Try egunparts
There's a lot of used ones on eBay.If you want a new one, Google: "Winchester, stock, long action or LA", you'll get a zillion hits.
Try Numrichgunparts.com
Lift the bolt handle, pull the bolt to the rear. Depress the trigger and hold it to the rear and you will be able to remove the bolt. Unscrew the takedown screw (large screw visible on the bottom of the stock) and you will be able to separate the stock and barrelled action. That's as far as you need to go. sales@countrygunsmith.net
Try e-gunparts.com, gun shows, gun shops, custom stock makers.