I know this doesn't help......much....but I had mine relined in brass by a sleever machinist out here, who unfortunately retired a year or so ago! Bummer for us!!! That allowed me to use the stock Fiat donut seals. Lee mentioned a well known eastern sleever.....White some kinda animal(?)....but I too have heard of issues with them.....that are not good for project progress...
Larry Stock had some units sleeved by the same guy that I did, but I do not know if he has any left.
Occasionally the stock units show up on eBay as some sort of Maseratti part....but if the Dino one seems to work with only a banjo change....may be money well spent!
I think the bore size was 7/8" or 21mm? Bigger (2cnd issue) Pantera part was 23mm often stamped on big nut on the end.
I do not recall any sort of pin in any banjo fittings....... but then I have a bad case of CRS also....!!! May have been done on later cars.....