In case anyone was thinking of hauling their logbooks out of the loft, just to narrow the search a bit, here is a brief history of 573. The units are all correct, but some of the dates are a bit woolly:
1958 CFE West Raynham, code letter L
10.62 CFE move to Binbrook
12.65 229 OCU Chivenor, code no. 97
1971? (possibly earlier) 4 FTS Valley, code no. 97
1980? 237 OCU Honington
? Laarbruch Stn Flt
? 237 OCU Lossie
1993 Storage Shawbury
Sold to Barry Pover, Exeter
1994 Flying again as G-BVGH
Hoping that this rings a few bells....