TASCO
The best you can afford.
Magnification, Distance, Objective size, etc..
depends on the rifle and the scope. Most scopes will use 1 inch rings for that type rifle.
Your Winchester model 25 rifle will take any size scope that you see fit to use as long as the rifle is drilled and tapped for scope use.If your rifle comes with a 3/8in.milled receiver rail then you must use that size scope ring bases.I recommend that a good 4X power scope is all that is needed for the effective range of .22cal rimfire ammo.
Best left to a good gunsmith.
Med or Large depending on the maker.
Best left to a gunsmith
50mm at least.I have found that with a 50mm objective you will need a minimum of high scope rings.Most medium hight scope rings will not give you the clearance needed for a 50mm scope objective.
The m1 garand for its power and it can have a sniper scope
Best left to a gunsmith
One that was designed for air rifles. Best will be determined by your intended use and how much you spend.