SydSpring

Seals that then. Fuel cell in the boot, and an underbody mounted surge tank. 

Won't work because the carby fuel pump is mechanical and mounted on the old xf engine  

XE and XF EFI wagons used an external pump, so there must be a way to do it.

I have a Barra swapped LandCruiser, it has two fuel tanks. The main tank has an internal pump, but the sub tank just has an external inline pump and it works with no issues. I believe it's a more off the shelf version of a Bosch 044.

Haven't had any issues with it, I think once fuel is sucked into the house and pump as long as you don't let it get dry you'd be fine. Even if it does go dry I'd guess it sucks it back up when refilled, but fuel flow is what lubricates electric pumps.

EFI wagons had a low pressure internal pump which fed the high pressure external pump.

I'll go with the epoxy primer then. 
Thanks everyone
Happy new year's eve

I'm planning on using spray cans since I don't have access to a compressor in my little garage 😂
Maybe I could use this epoxy spray? a bit pricey though: https://vgautopaints.com.au/collections/primers/products/eastwood-2k-aerospray-epoxy-primer-gray-aerosol
 
If I went with the etch primer, how do you "blend" the bare metal to the existing paint since the etch primer cant touch the existing paint? or is a little bit of overspray ok

TBH i wouldnt strip it completely unless it is really bad. you can just clean up the rust affected areas and key all the other paint if it is sound. Really depends what you want to acheive. certainly stripping to bare metal etch prime, prime, body work, base and clear is the way to go for a restoration but if you are just doing a  tidy up theres no need to bare metal the bay.
 
Ive done both ways and each looks equally as good, one just take 100s of hours more than the other.

The only difference I'd say to that is instead of etch, use ppg epoxy (or similar) after you sand the bay. It will permanently seal the old paint and bare metal at the same time and give you a consistent base layer to work up from. The stuff I use was called ppg 408 grey-green but it's had a name change that I can't remember the new code.