Lovely Set of 3 Antique Drafting Triangles serving platter and a small possible very

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

4 1/8" x 3 3/8" x 1 5/8" t and in very good vintage condition

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

with light wear and aging to the metal

Lovely Set of 3 Antique Drafting Triangles serving platter and a small possible veryI 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