You know the saying ignorance is bliss, well now that I have been "educated" (looked up the tool Sam suggested and that lead to YouTube, you get the idea) so much for needle files and a honing stone. Debating making one of those ring filers---looks like a Dremel cut off wheel should work--HAND CRANKED, of course. And here I was trying to come up with a slick way to grind the valve stems without having to send it back to the engine shop (actually got a plan for that).
Looking at other postings today (Zippy), I know 2 guys that would not vote for the 18XX machines as their favorite.
At least the 2072 and the 982 came effortlessly out of hibernation today so dad could mow chickweed and onions.
Well, got 3 options: buy, make, or borrow one of those tools.