I picked these mags up in a package deal today and would like to more know more about them such as date, value, era, collectability, anything. Two are marked "C-R" on the bottom of the base plate and "R" on the topside lip of the baseplate. The other three are unmarked other than an "R" on the topside lip of the baseplate. Also, one of the "R" only marked mags has a pinned base, the rest are welded. All have the same dimpled follower. Any help would be much appreciated.