Lovely Set of 3 Antique Drafting Triangles serving platter I'd love to know the

I'd love to know the story behind this one--whether this silkscreen was made to print the logo of an actual "Private Eye" or a fictional one

) And this I think is an exceptional example in the quality of the portrait and detail of the pin pricking

with a little minor staining/browning here and there

and a small possible very thin black ink mark on one side

5 3/8” across with tail

Lovely Set of 3 Antique Drafting Triangles serving platter I'd love to know theI can't resist these when I come across them; they just make me want to sit down and make geometric drawings. I found these three together and have to think they have been together for a long time, together making an excellent set. The dark one was once marked as a ruler on the hypotenuse; now mostly faded, but a few inches remain visible. The scalene triangle is marked with a Sphynx logo, which I have not been able to place. I'd guess all three date