RE: OS 46 SF ringed ot ABC
You are on to a gem!
I don't now if the ABC is chrome or not but the SF never exhibited the peeling liner problem of later OS engines.
I have several of these engines and really like them a lot.
The ABC version does not have a piston ring.
Your running in techniques are allright. I don't think you will need a heat gun though.
/Red B.