I know it's a bit late but; I run them up hot, spray with penetrating fluid then have a go at them. Haven't snapped one yet.
I had that for so long. Awesome picture.
Not really one for posting pictures but I'm bored.
This is what I have been upto/in the middle of;
US markers into a UK rubstrip
One side is now finished. Still need to do the other.
Smoothing wings, which will then be rolled.