What distance should I see between studs in a wood frame home built in 1943?
16 inches on center.

Note that lathe and plaster has a number of advantages over more modern drywall, but studfinding is not among those.  A standard stud finder you might buy or rent is likely to give confusing results.  However a super powerful magnet, or a magnet based stud finder, will work just dandy.  A row of small nails runs up and down each stud holding the lathe strips.

Removing the baseboards probably won't help at all.  Often, but not always, one edge of an electrical outlet aligns with a stud.  Framing can get funny near doorways or windows... the magnet is your friend.