Removable Scuttle

[Garth]

As I have nothing better to do I removed my scuttle today with a view to leaving the vertical (firewall) section in place and fitting rivnuts in this vertical section to re-fix the scuttle.

All relatively straightforward, but just wondering how people who have done this have dealt with the heater box? There were about 7 rivets behind the top flange of the box which was just stuck over them with silicone! Looks like one needs a reasonable seal between the top of the heater box and the scuttle. If these rivets are replaced with bolts they will protrude much further than the rivets did? Is the answer just to use button heads and lots of silicone?

Ideally not silicone so it is easier to remove in the future?

Could one use a neoprene seal instead of the silicone and screw right through the flange (and the neoprene) on the heater (probably with a thin s/s plate for strength?).

Any ideas welcome please.

Thanks

Garth