Many thanks Gentlemen.
It's been in the car for 8 years, and has covered 60k Miles. It's obviously been used as the service history shows replacement filters etc.
I can only assume that it has been running well up until the owner had problems (2014), spent a shit load of money on replacing the TB, DIC, etc to find nothing fixed it and traded it in for something newer.
I'm in the fortunate position where all things which go wrong with this model of car have erroneously been replaced due to either bad information from the owner, or lack of research from the Indy.
From the above, I can deduce that the LPG components fitted are more than capable of handling the fuel delivery the engine needs. Interestingly, I've taken it for a 80mile blast tonight on Petrol. When I say blast, it was obviously on a private test track and in no way shape or form was a Civic Type R involved. Anyway, I digress.....
On Petrol, it runs bloody well, perfect in fact. On Gas it runs perfect, until you give it maximum beans..... Seems to fuel it ok until lock-up in 3rd, and then it all throws a wobbly, and back onto Petrol.