Would like to thank everyone for their interest and suggestions.
First set will be going out to Duckhunter, maybe get some feedback and suggestions from him.
Regarding SP2 stacks: seems i can get a new oem one from CMSNL here in the Netherlands for $ 20, cheaper than sending overseas i think ?
So I will be ordering one from them and keep you updated about progress.
In the meantime if someone could check the diameter (see picture above), that would be very helpfull. If this works out on my lathe, i can order up some Delrin and get started.