[Amps] Capacitor

[Zgieb]

      Has anybody any information or links on old TCC (Telegraph Condenser Co.) 
      ceramic high voltage capacitors please? Usually referred to as "mushroom " 
      style.  Are marked T.C.C. "KO.3551/S". 
      However is marked 1200pf. Grey, tubular, approx 28mm diameter and 100mm long.                                                         Breakdown voltage? Suitable for rf coupling/decoupling?                                                                                                          
      Is the KO number a catalogue range or just an MOD supplier/factory code? 

      Thanks! 

      Andy SP6AEG