How long is it since anyone has seen or bought a tube with a cycle valve (not Schraeder or Presta). I have a couple on old bikes hanging up, but I think it would be about 30 years since I last bought one. They must still be around somewhere in the world, as cheap Chinese and Taiwanese puncture repair kits still have some pieces of valve rubber in them. It's even longer since I saw a new rubber-type valve as compared with the spring-loaded type. And those rubber valves are very hard to pump up.
Cycle valves on the tubes would look the part on restored old bikes.
Might be worth trying Clarke cycles Magill Road
I remember having them on old dragsters.. this link says they're still in use, if you believe wikipedia.
Yeah, my 7yr old son just the other day picked up a valve sleeve bit of rubber and aked what it was - every single puncture repair kit I have bought the past few years has included 2 of them .. kind of odd I guess ??
Anyone wanting these types of valves ie the metal bits - I have a handful, Just contact me.
Often get old bikes donated with them.
We routinely replace them with car valve type inner tubes.
I just looked in my puncture kit that I carry for the BSA, and noted the valve-related bits.
I have:  Valve cores for Schraeder valves, short and long. I don't have an intermediate length one, but the short ones will fit any Schraeder tube. (I also don't have a refrigerant-grade Schraeder valve core!)  Valve cap for Schraeder valves, with core remover built-in.  An ordinary Schraeder valve cap. I prefer metal ones on the bike.  A cycle valve/Presta adapter. This is in addition to the one on the pump connecter.  A cycle valve and a spare lock collar. I have never bothered to remove these after removing the last so-equipped tube from our bikes. You never know when it might be needed...
It is a good idea to carry a spare short-style Schraeder valve core, and a suitable tool (e.g. the special valve cap). These cores do sometimes fail, particularly if they get grit blown in via the pump. The spares are available at your (automotive) tyre dealer.