Since a M-3602 is already pictured by someone else there's no sense in showing mine, they look the same, but I saw no mention of any other markings on the one pictured so I thought I'd show this. I picked this one up a couple of days ago, it was buried in a corner under tons of stuff at an antique shop here in Spokanistan. My eye just caught part of an insulator under all that stuff and I went to digging. This building was as antique as the insulator, the stairway was way narrow too, built for skinny people, which I ain't ... and it nearly killed me with my bad back lugging this huge piece of porcelain down those narrow stairs. Anyway after digging a path to this piece and hoping there weren't any chunks out of it, I found the monster chip free, it was filthy though, it looked like it'd been under that pile of stuff 40 years. After all that work, which I should have charged him for because I know I heard him say once or twice, "oh I've been looking for that for years", I got the piece for for $15.00 Anyway, notice the incuse G.