2006 (04) Queen's 80th Birthday - Westminster 'Mercury' Official's (x 8) - Doubled 2016 90th Birthday Set

Astonishingly good Westminster 'Mercury' single stamp Official's (x 8) as issued for the 2006 80th Birthday issue....

But then a collector has Doubled the set with multiple stamps from the 2016 90th Birthday Set.....I counted 21 stamps from that Stamps & M/S set added to the covers !!

I can't see anyone else being this mad, so this is 'probably' unique... !

Code: 67214