Old RAF Ternhill callsigns

Does anyone know what the 6 FTS and 7 FTS callsigns for the 1950’s,specifically the Piston Provost era could have been?

I have a beauty on Fs2004 with repaints for 6 and 7FTS kites and I’d
really like to have ’em with the correct callsigns if possible.

Many thanks.