Hi mate, could you not get away with a bore in the profile, then make a plate you could fix the FK mounts to, then fix the plate to the profile ?

Just noticed no one had replyed to you thats all, i'm thinking it maybe a better way to go as well, fixing the FK's to the profile maybe a little tricky and not necessarily the securest way of going about it, i say that with out knowing the wall thickness for your profile.

.Me