Looking to narrow down a change from the roll-pin retained latch pin to the use of the threaded shoulder bolt.
I have reports of a Feb 65 car with the pinned latch handle (top large of "bolt" latch handle pivots on is solid, no phillips or allen head) and a July build car with the threaded version. Which leaves a 3 month window...
Any build dates between those dates with known original top frames that some folks could check and report on...