Joe L ---

I haven't yet disassembled a wasserleaker, so this may be a dumb
question.  Moving right along....  for aircooled VW heads, we used to
put a little valvegrinding compound and oscillate/rotate the cylinder
jug in the head.... until we got a nice even surface finish all round
the mating area.  [Of course you have to be sure to clean all the grit
away afterwards.  Maybe the dishwasher while the wife is asleep...]
Never any pops or whistles in the engines we rebuilt.  Would this
procedure have worked for your purpose???

Thanx
Glenn

PS:  I assume you followed the discussion on Dex_Cool some weeks ago.
You don't want to repeat leak fixes any more often than necessary.