just got a few modules back that were on-loan to a friend for years; he lost one of the stock Randall module's knobs. Poked around & couldn't find any classified listings or Reverb/eBay listings that said they were OEM Randall knobs- does anyone have the exact specs? I'd prefer to find a single one (or set) identical to the stock part, alternately looking for a set with the same diameter & style (black plastic, ridged edges, with white line marker).