Piston rings

A few months ago I was witness (party to?) a frustrating moment as a friend attempted to free the rings from the piston of an ancient scooter he was rebuilding that hadn't run for years.  The rings were well stuck (though not welded in, so certainly salvageable).  He'd been soaking them in penetrating oil but was now very keen to get them out and so with the help of some heat from a blow-torch we set about getting them out.  Alas, we were too hasty, and sure enough we snapped one ring.  Under normal circumstances this might have simply cost a couple of days and a couple of quid, but as the engine was rare, it took him a great deal of effort to source a suitable replacement.

If any good was to come out of that experience, it was that I learned a valuable lesson; or rather it reinforced a mantra "patience is a virtue".
As a consequence, I've been soaking my Manurhin piston and seized rings for many weeks now - ive been in no rush.  This morning however, I decided to get proactive.  While the wife was still asleep in bed, I popped the piston on the kitchen stove and set it to boil.  Every now and then, I whipped it out, gave the rings a little tap around with the wooden handle of a screwdriver, squirted some WD40 on, let it cool..... and then repeated the process.
Hey presto, the rings eventually let go of the piston and sprung out like new.
A little patience and some gentle persistence, and I've saved myself a lot of heartache