Lot 41239 – 1919 (May 18) Hawker & Grieve 1919 (May 17) Env

1919 (May 18) Hawker & Grieve 1919 (May 17) Envelope with 1919 3c Caribou and Great Britain KGV 1 1/2d tied by mute cancels, with Post Master General’s oval ds adjacent, reverse with London « Found open and officially sealed » label with London cds, incl. original contents « H. G. Hawker is making this attempt on a Sopwith biplane (Rolls Royce engine)… », fine and rare