Unique Vintage 8 Unique 1944 Laminated Graphing Paper With Tilt Perspective

Rare 8 sheets of Truper graphing paper with tilt perspective. Each sheets has been laminated and is marked Downs & Sons Copyright 1944. Each sheet has a different degree perspective showing the graph from a viewing angle, ie 5° looks as though you are looking at a steep angle - 5° from the plane. Unknown what the original purpose of these unique graphs were. The 80° sheet has an original corner torn before it was laminated. Any information regarding these sheets would be welcome! Offers also welcome, would love them to go to someone who can appreciate them!