Sadly the tape didn’t work. I assumed this was a wheel I’d taped myself but is actually a factory done one. Looked at the valve surround and you can see it’s worn and had a hard life. This came with an old set of wheels.
Plan this morning was to cut up an inner tube and fit a square of it around the valve, simple enough to push through cleanly. So that’s now done, it’s inflated and we’ll see if it leaks air today. If it does, I’m off to Banjo cycles for a pair of new valves.
Just so you realise I’m not a complete gimp, I have 4 other wheels running tubeless that are fine!