Its much closer to 113s than most 111s. This may be a slightly smaller rectangle, but except for early 111s ie the 2.2 series, on every 111 that I can remember (which is a fair number) the pattern was much more akin to a leather grain, incidentally, the original which I scraped off of this firewall was absolutely "leather" grained. My '67 250se Cab with 67k orig miles has the leather look, my '69 280se coupe as well. I think my 356a Porsche engine/trunk/floor tar paper is the most 113 like I've seen. Someone should order some 113 firewall "cardboard" and see what they get!
kb