Whilst mosying around the interwebz trying to find valve thread specifications, I found that no-one really seemed to know. And the interwebz couldn’t tell me.

Until I found this, this morning.
Not 100% sure of accuracy, but I think that the presta valve spec is one of the french ones

https://law.resource.org/pub/in/bis/S13/is.532.2006.html

This, combined with this handy set of pictures: http://www.nandanworld.com/tube_valuves.html

I think that a standard presta is maybe the “French Valve for Jointed Tube”

Anyway, just chucking it up for posterity.

Move alone, nothing to see here.