I don't recall seeing paint on early A's for the rear ends and springs. (but I never looked real hard either.) but I do know they used orange,red,light blue, bright green and bright yellow as marking codes on some parts (Green,blue and red were from me watching shift marks 1st second or 3rd shift) I mostly saw Green for 1st shift and blue for second shift.
The shocks were a Bin only difference as far as I saw when I did walk through (s) at Jefferson. They(the workers) looked at the cards stuck on the car and went to the bin for the shocks and bolts. rear ends already had the springs,brake lines and if required rubber snubbers attached and were jacked up into position then bolted on. front k members were raised to the body complete with engine/transmission and wiring attached to it. (or the car was lowered over it and the rear end too, they were jig mounted and over a walking pit. Depending on the specific assembly line that they were using, 2 of the 3 lines I was allowed to watch lowered them to the k member, 1 raised it) it was nothing like current days assembly line it was a LOT of manual labor and overhead reaching work putting on parts. I must have spent nearly 3 weeks (all (12) of the mechanic's and (6) body men rotated going to the plant) going to the plant and just watching them put together cars . It helped us figure out how and what to remove to replace parts needed repairing a lot easier.