Reassembled the spar components and reamed holes for AN6 and AN5 solid rivets.
Image 2) Geoff suggested cutting away spar cap angle around rivet where caple anlges butt so that at least the rivet is set solid. Zenith already said the cap angle doesn't add to computed strength (hence approving the two piece cap anlge instead of a single 10'+ cap anlge) so this approach makes sense to me. Will do this next weekend.