Chip away and enjoy the adventure in hunting them down.
One good thing about the PT with less fins is they are newer. I have one I found without a starter and primer cap needle and seat, and after adding the missing bits, it runs like new.
I bet you are in the situation wher you have more engine husks than starters to go with them.
I got a good score recently where I happened to see a guy loading a derelict Victa with PT tho go to the tip and I said hold your horses what bits can I get off that? Well it turned out the starter was good. Thank you!! Also managed to get a pair of good rear 7" wheels. Perfect for the front of one of my "pets".
I wanted to grab the primer cap etc from the carby, but alas the guy originally throwing the whole machine decided he wanted the whole throttle, snorkel and carby set! Guess I couldn't begrudge him that.