turn signal switch for my 64
I think a 69 Dart turn signal switch will work in an early A, and those are still available (think). I suspect this because I had a 69 Dart and a 65 Chrysler. I had a new switch for the Dart (probably via Paddock) and used it in my Chrysler. I just had to file a little plastic off the base. I later found the correct cancel cam for my Chrysler so I have the new 69 one out. When I recently worked on my 65 Dart column I compared the switches and recall that the 69 one should work.
A few other things to consider:
My 65 Chrysler is different in that it doesn't have wires on the cancel cam. I think because it has so many rear bulbs that it they didn't have to share a filament for brake and turn signal. When I had the 69 switch in, I didn't use those wires. I kind of remember that the switch in my 65 Dart does have wires on cancel cam. Even though it has 3 rear bulbs on each side, I recall it still shares a filament for brake/turn. The bulbs in the trunk are just extra running lights. I was just repairing that wiring last night, so will check. Look up my prior post on the steering column and the photos may show the switch. The 65 Chrysler switch looks more robust and is still working fine, the plastic tabs just broke off the cam, and if my wife drives a car every control must be perfect.
69 switches use the same connector type (don't know the name, and you won't find those new today). It is easy to release the pins from the housing with a small screwdriver. Don't cut the wires. Some idiot did that on that my 65 Dart and reconnected with butt crimps. I fixed that mess. I looked at the connector for a ~73 Dart in the junkyard and it is totally different.