So, my A5 sized piece arrived, and I marked up the oddball shape that I needed for the first piece. On the basis of 'nothing ventured, nothing gained' and that I had more material than I needed, I attacked it with the electric fretsaw. To my amazement, it went through it like a hot knife through butter. I kept it fairly slow - probably about 1 mm per second, and although you could smell the cut, there was absolutely no blade clogging or melting of the swarf at all. Nice finish on the edge. When I cut the next piece, I might even put a new blade in, if I can find them ... :-)
Arfa