RAF Wyton English Electric Canberra wing tip fuel tank engraved square

These interesting squares are cut from a wing tip fuel tank of an English Electric Canberra. The tank has come from RAF Wyton and was used on multiple Canberra aircraft including the likes of WH902. 
We have chosen not to specify a single reg as these tanks were moved around. 
Squares are approx 9.5cm and come with certificate of authenticity.
Price is for one, photos examples only. Imperfections due to long term storage and operations. Will come engraved as per example in photo 
The photos show the full fuel tank and it cut into two separate sections.