Picked up a 1948 model 70.270. It's missing the rear sight. Would like to look around for one, but need some help on what it should be. Can anyone help? Pics would be great?.. Thanks.

Assuming a standard rifle it should be a Winchester 22G. It is a leaf spring sight that used a rear step elevator for adjustment, most likely the 3C. I don't have any pics handy but google images is your friend.

They had the milled long flat type, with elevator. One piece milled; not the post 64 folded dovetail ones. Same as on pre 64 Model 94s too. I have them; for $80 shipped.
Now, if you have a FW, then it is just a Marbles type flip sight.

A quick search on eBay turned up 10+ sights and elevators for sale..

Be careful; many Win 70 sights there are post 64; and nice ones go for over $100.