The stave that was warping and cracking is now back to being straight. I've got a busy week so it will have a few days to settle down, I'm going to leave it strapped to the 2x2 on the warm radiator and then probably give it 24 hours back in the garage before starting work on it again.
Mean while here are some pics. The steam has draw out some purplish colour from the wood, and some of the cracks have opened up from the central pith to the belly. The cracks look alarming, but they are very shallow, much better having them coming out to the belly than running deep into the bow. Dunno how the stave would have been if I'd used the side with the wider rings and didn't have the pith to contend with, however that side had the natural deflex. Who knows, but the received wisdom is that the tighter rings are some how "better", not that I have any real evidence for this. My decision for cutting was based on the the clean state of that face of the log, the look of the sapwood and the reflex. The other side which was cut off, doesn't have enough thickness left in the centre for a big bow so I can't make two bows and compare. We have to work with the wood we have in front of us and live with the decisions we make (no charge for the homespun philosophy!).