Distributor Vaccumn Advance

I have a problem with what Distributor Vaccumn advance I should purchase for my 71 Mach1 fastback.
The engine is 351W 4V. When it was installed replacing the 302 I have no idea.
My Distributor Vaccumn Advance needs to be replaced. There is a metal tag on my Distributor with the numbers D8AE-12127-JA.
I have not found a way to find out what the numbers represent but was told D = 70s, 8 = makes it 78, A = Ford (Full size like LTD), E = Engine
Group, 12127 = Distributor, JA is a revision/version.
If that is correct also told the VC-229 would be the part number. Found this one on eBay https://www.ebay.com/p/227924661. Very good price compared to auto parts stores. Also if not correct have to pay 20% restocking plus shipping.

Pics of current part attached.

I found the correct part and have replaced it .
I did learn 1 thing. Good idea I got from a video, have a magnet. The thing I learned not to do was leave the tiny clip stuck to the magnet. When trying to put the clip back on was hard. The tiny clip had become magnetized. Every time my friend and I got it in place with small screwdriver and or pliers it stuck to the them and moved out of position. Finally got it snapped on. I would say it took twice as long as it should have.

Thank you