I had a ‘93 cvh efi same as you. I’ll check if I still have the details you need. I did send a copy of the handbook to Gomog to be made available on there. I’ll look at it to see if there is a part number. I think I bought one from Halfords back then but they have changed their stock numbers since then.
Just checked gomog....no oil filter part number in there.
Here’s a link....
https://www.gomog.com/allmorgan/allmorgan.html
