I would see no need to reinvent the wheel here. All of the parts for your system are available here.
https://www.oldairproducts.com/categ...lacement-parts I recently bought most of my AC parts from them. The qualtiy was at least as good as OEM, possibly better on some items. I am also converting to 134a while i'm at it. I would highly recommend using a new compressor. They have improved shaft seals to take care of the leaking shaft seal that ends up slinging all of the oil out the front of the compressor. Both new A6 style (OEM) and after market styles are available. None of the remanufacturers use the new double lip seal, but if you rebuild your compressor yourself they are available.