Not sure if this is how they were made or not, but they certainly look close! So I'm happy with that
I can't help but think of Occam's razor though, where the simple answer is often correct! These are tools they would have had laying around on the bench so it seems plausible at least- the most telling thing to me is the uncanny resemblense of how the vertical lines lay just below the horizontal and have that ribbed look. I just havnt seen anything else that reproduces that.
great work! I'm amazed at how very similar this looks to ILM. looks dead on to me