I might invisibly relieve the contact point with the metal point of the scallop then glass the crack. Acraglass thinned with acetone is great for strengthening and sealing the head of the stock anyway...soaks in like water, then sets up. I wouldn't sweat it too much. BTW I once glassed a scalloped action pre-emptively, and it actually CAUSED a little crack like you have! Good luck. Steve