I think without factory documentation you'll never know the original SPD. If you are just looking for a general time frame to help find date coded parts, 'the last week of January' is probably close enough.
Do you have any vins with a build date from 1-29 to 1-31? If so how close are they? Do you have vins out of date order and if so how many and how far apart by the number of days?
i've got a xxxxx9a222104. thought it was built 2/5/69
That is about 1500 numbers off the 9A219655. Maybe there was a plant shut down or the tag machine was down a couple of days. I don't know. 69CoronetRT what do you think.
