bright yellow oval ceramic dish

This little oval dish was a recent Goodwill score (for a buck or so) simply because I like its cheery bright yellow color (which happens to fit with my vintage pastel yellow countertop tile perfectly, where it is pictured?!) and because I tend to find dishes of this general shape very useful to heat up leftovers/etc. ;-) :-)

I'm under nobody's impression that it is particularly "old" by any standard, just showing it in case somebody else might recognize something about its underside marking (which reads: "CALIF. USA OVENPROOF") or maybe know of a restaurant chain that uses similar dishware, or a chain store that sells a line like it, or anything??? Frankly, I'd love to have a little stack of 'em (instead of just the one) especially if they also came in bright *red* -- I only have one other sorta like it (a little smaller, in white, no markings, with different handles, likewise probably not very 'vintage') which is absolutely a regular traveler thru my dishwasher due to frequent usage, no doubt like this yellow one will now be. :-) :-) :-) It measures roughly 9.5" long and 5.5" wide.