ancient Avon sib has metal Toggle the table of contents Schrader valves hum?

[achillies-14]

So I picked this huge sib up. it was a RCMP boat so maybe custom, who knows how old it is but it has metal valves. Does anyone have any info about these valves and if there is an adapter for newer ones to fit maybe? thanks

I have a link to a Facebook post about them with a picture, as I can't put pictures here thanks https://www.facebook.com/photo?fbid=...60259963948106