Arrr! "An eye for an Eye!"
I would remove the remains of the old bolt and then epoxy in the hole, adding some layers of cloth on the inside. Not an easy part of any boat to work in; perhaps a helper could hand you stuff once you get an arm or two and a light wedged up there to do the work. Not very technical work, just annoying and a bit tedious.
("Been there, fixed that")
Best,
Loren
ps: pick up a copy of the West System epoxy manual -- thin booklet but packed with information.