i know you guys dont like parting with your engines, but how's this for an offer?!
I'll put together an LPG conversion kit for your petrol engined car/4 wheel drive (with new parts) and swap for a nice stationary engine (eg restored appletop or a horizonal hopper engine). The approx. value of the LPG kit would be £450-650 (depending on spec), but would be interested in part-exchanging if required.
Any takers?