THE TROUBLE...

...with maple is that it tends to remain susceptible to changes of humidity many years after you'd think it had settled down.

CC hates maple - he doesn't trust it...
I love maple - I've sussed it!

Should have photographed the original crack which was spectacular.

I cut around it with a very sharp blade. The back had become swollen on the inside due to humidity which caused it to spring away from the braces & to split, as I said "spectacularly'".

I glued the back down to the braces, then I glued in extra supports (with the red stripes) - these little clamps are gluing an extra support! Next week the gap will be filled with some of my old maple...