This cover commemorates    the 25th Anniversary of the Taking over RAF North Luffenham by Royal Canadian Air Force 

This cover is   RAF   

It is signed by    Hank Buttelmann    US Air Force  Pilot    Korea 

This came from an extensive collection of RAF Covers built up over many years by an avid collector  . Many of the covers were personally sent to RAF and other World War 2 participants  to be signed and so are possibly unique . In some cases the signees details are written on the flap of the envelope

There is NO insert

It is a flown cover with amended label in the envelope 

RAF 37 Numbered   #  46