[CNGBiFuel]

Yes, forgot to answer that part of your Q. You wouldn't bother to swap a factory set-up. It's good if found working, and great for what it grants when it isn't. But not good enough to actually trouble to move. And not so terrible that you'd remove it for a more advanced system. Truly, when working it's 'good enough'. The LPG trade don't like them becuase they're awkward to source parts/diagnose which is a fair point. As 'Classic' says the factory set-up is pretty much nailed-in anyway.

A factory system is also good in that you don't have to declare any modification; although most insurers no longer 'load' LPG premiums by much, or if anything - but bear this in mind.

In short, if you find a 'factory' you're better off. Find one in good order and you're laughing. Then even if it falls-over, and you convert to the sort of whizzbang ^^^ 'classic' ^^^^ puts in for a crust, it's maintenance, new-for-old. Thus not a strict modification.

And a conversion falls in, no bodge-drilling manifolds etc etc, and you've a proper factory gas-level fuel-gauge rather than lash-in LED things by AEB et al.