The chassis is definitely not a Lola and the rear upright in the plastic tub is definitely from a Lola FSV, P/N D210/4014, which was used on all A/C...
Pretty much EVERY head surround I've even seen used is 'terminated' by a single 'push release' PIN on each side at the front. It hasn't been obvious...
Are the studs backing out, or are the nuts loosening on the studs? its easy to determine, just put some witness marks with a sharpie on both ends of...