New latch and striker plate.............but the reproduction stuff can be problematic. This has been a known problem for 70 years. My wife fell out of relatively new '50's pickup when she was kid. There is a really good reason this type of stock latch was redesigned.
Seat belts and Altman bear claw latches.............
http://www.triquemfg.com/altman-easy-latch-for-1947-51-chevy-truck/That said .........There are several posts on latches, adjustment and rebuilding of the stock latch in the door section.
