Found this site and glad to see all the interest in these old boxes, except for the prices of them going up

I still have a couple of my originals a old Sanyo and JCPennys from back in the day plus I have added a few.  Seen this forum for parts wanted and figured I'd see if there are anyone with donors. 

I'd like to find a slider for the JCPennys and ditch the ghetto chrome job I stuck on there.  Also my Sears SR-2199 is missing a couple knobs too.  It's my garage radio and a bit on the beat side but still jams out better then any others I have. 

eBay never has to have any so anyone got any ideas where to find them? 

Thanks