LPG kit for Disco 1 - DIY

Just bought a second-hand LPG kit for me Disco 1. It has 2 underslung 40 ltr tank, but I want to put the tanks in the boot as it's me off-road toy...

Anybody have experience with doing this? Any advice to offer? I know I need to find a way of venting the tanks externally, just not sure how to do it... they are 4-hole tanks and don't have a 'gas tight box' over the valves, etc..

Would I be better off just getting a single large tank & vent pipe kit from Tinley Tech and going with that instead?

Don't know anything about LPG, but, I would have thought it would have been safer and better to get a tank designed for internal use than risk gassing yourself to death...

Tanks are all the same as far as I can see... ones for internal use have a gas-tight box fitted over the valves leading to an external vent.

Either way you can do it, get sealed units for the old tanks or a new tank, if they do leak on the test they will fail and you will not be issued a cert so up to you which way you want to go