Broadside,
1. my original tank sat directly to floor, however i took my tank out thru the firewall. the floor was patched by a PO.when I put my tank in i used the rubber grommets on the tabs to re-secure with bolts and washers . bolt with steel washer thru fiberglass, rubber washer tank tab , rubber washer ,steel washer, nut. it was a real PIA.
2.i put a thin bead approx 1/16-1/8'' of the buytl rubber putty. just enough to keep water out stuck to the top inside corner where the trim just touches.
3. once again PO ,what I removed was a thin piece of something close to cardboard, not plastic , and not leather.
4. just me , I'm tucking the fabric under the windscreen gasket.
dakazman