As an introduction though, why not go to the Blog overview first.
The alloy fuel tank sits up against the front upper bulkhead and is bolted down using M8 bolts, spring washers, washers to the tank support strap on the LHS and the LH pedal box support angle. M8 riv nuts need to be fitted/will have been fitted.
This shot shows the M8 riv nuts being fitted in the rear of the pedal box angled supports. Note the Masterfix ratchet riv nut tool,(also marketed by Wurth) which in my experience is the best manual riv nut tool without doubt...until I find a better one! I also use an air riv nut tool.
I've displayed this shot deliberately as it shows a potential hazard. I almost fell foul of my own mantra as I've not really allowed enough room for the tool when drilling the holes for the riv nut. You can see the tool just touching the steering column plate. One should always anticipate entry and exit of a tool when planning the position of a fixing...easily overlooked though.
Here is the LHS of the tank mounted down through the tank support plate into the tank support strap. The tank needs raising slightly to allow the electrics box cover to just slide under, so I've placed spacer plates under each side. Looking recently at photos of the best client built car, and I always look for details, in my view the above bolts should be replaced with socket cap head bolts.
These last two shots show the tank in position, bolted down with M8 bolts, spring washers and washers. The tank can be removed as can the plate beneath, thus giving additional access into the tunnel. Remember, for LHD, these photos would be reversed.