I am having a bit of a gloat. I've finally managed to find a GSTP watch, from a local boot sale this morning. It is a Swiss made Recta, black face with Radium hands and figures, complete with the leather strap and T pices. Working nicley and has never been touched. The only issue is the snap on back plate is sligtly bowed in and a bit losse, so will get a real expert to deal with that. The markings are the Broad Arrow G.S.T.P. from 1939/45. GPST stands for Genral Service Time Pice, or Tempary Pattern , or Trade Pattern, take your choice. The question is (Clive? Oh Font of all numbers) The numbers on the outside of the case are F, possibly 0 or leter O , genuine looking poor strike, 22166. Inside the cse, presumably the movment number , is 621242, very clean strike. Is the outside number traceable?