Tyre valve stem leak

[Avocet]

To be fair the OP does seem quite sure of himself, unlike some others.

The hallmark of a fool!

 

[Avocet]

No doubt people think this is faffing. But, I think this is leisurely research.

The valve stem base for the play wheel is easily accessible. For my regular use wheel, the stem is deeper in. But, I don't think it will be a problem. The stem can't be rotated because the rubber has bound to the metal from heat cycling and ageing. The rubber feels sticky as a sign of aging. Synthetic rubber reverts back to crude oil over time. The valve base is positioned to interact with the tyre bead during mounting/dismounting and inflation.

View attachment 417150

Crikey! Looking at that rim, it's not just the backs of other cars he's fond of driving into!

 

[yorksbuilder]

a sign of aging

your're not joking. The perishing and shine on that tyre makes it look about 7-10 years old!