It's a rocking print tray! I think Nikor was one maker, maybe also Soligor. You put your paper in there and a little bit of chemicals and rock it back and forth, sloshing the chems over the print. Kind of a cross between tray processing and drum processing :-)
Yep, rocker tray, also called a "canoe" tray because of the shape. There are other types of rocker trays, but yours is a true canoe tray. They are supposed to save on chems.
Rick A
Argentum aevum
BTW: the big kid in my avatar is my hero, my son, who proudly serves us in the Navy. "SALUTE"
"Political correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end."
A remnant of the 70's: a Mitchell Color Canoe - sold by Heathkit.
Well, the Mitchell Color Canoe is probably going in the trash with the bell bottoms and my old Heathkit timer, which magically died the day I bought my f-stop timer from you. Coincidence? I think not.
I believe they were for color, but they could be advantageous for the extended times, and higher temperatures, of lith printing.
Don't toss it. I think you'll find a lith printer willing to take it off your hands.