Sorry lads, just got back in. Will definitely get a gas bottle then. Not doing a lot of welding, Thor. New plate on each end of gearbox X member, about 40cm each end? Then a small amount of welding on the rear tub support tubes. Estimate 1.2m of linear weld. Via Amazon I've bought 0.6mm steel/copper covered wire and a box of 0.6mm tips to match. Another mate in the pub tonight said he would drop off a CO2 bottle tomorrow, from his welder. So I'm hoping I'm sorted for that amount of welding.
Thanks for the advice, lads.
Good luck. But rust can be a nasty immigrant and really **** you off