I persevered with the rolling pin ....trying to square it up was a right royal PITA as whatever this wood is it's really hard and took ages to cut through
I've cut out the needed neck heel extensions for both the ES-3 and ES-1 builds, plus the extension that will run down the side.
The two heel extensions have just been glued and clamped a few minutes ago, so once they are dry I'll shape them and use some filler if needed to get it smooth [I've got more than enough saw dust to mix with timbermate to do that ]