As noted yesterday, I duct taped the hinges on the cowl side and applied flox filler into the gaps, then top coated with dry micro. Hopefully after this fully cures (about April now that the garage is so cold), this will sand down nicly and the cowl will come free with a nice smooth joint.
Note gap where the hinge mates. The cowl was trimmed too short here.
(Rt side) Gap filled with Flox and top coated with dry Micro
