Hey Jonathan, that's awesome.

Do you have any none return valves in the fuel line, or any other gizmos?

No valve fitted. The only thing I have as an addition is a filter, which is fitted between the pump and the carburettor. I did have a non-return valve fitted at the front chassis leg but it's no longer fitted. I will say that it doesn't always start immediately. It can sometimes be a RRPITA (Right Royal Pain in the Arse)

The Deuche has been sat, unused, for over a month. On Sunday I needed to move it to the other side of the drive to allow a skip to be dropped in its place on Monday (just had the front garden landscaped). It took the best part of an hour before it ran on two cylinders and didn't immediately cut out. Fast forward to this afternoon; the skip was gone and I needed to put the car back in its usual spot... it refused to start again. I ended up popping over to my local GSF Car Parts store and buying two new spark plugs. Fitting was a bit of a 'mare, my plug tool is the wrong type for the tight space between the plugs and the inner wings. I had to loosen the wings to give me enough space to get at the plugs. The wing nuts were very rusty Anyway, with brand new spark plugs fitted the engine started immediately, and ran sweeter than it has for a good while.

Lucky the car wasn't in the skip like in Victor Mildews...
https://www.youtube.com/watch?v=pOiB-jmU2PE