Unless different for the 'Vairs, those look like standard 64-66 C10 truck style dog caps?
If the same, they're common enough and often on eBay...repops in chrome only are available from Classis Industries @ this link...
http://www.classicindustries.com/sho...el-covers/?p=2
Good luck, cool truck!
[img]<<GRAEMLIN_URL>>/beers.gif[/img]
~ Pete
