Markings are:
87/5
21(9?)4 (the "9" looks like a line with a symmetrical circle on top. Like a balloon or lolly pop)
20/
8x10
2t or + same "9" as above
5
It obviously needs cleaning.
I can take additional photo's if you would like.
We bought it at an estate sale in the hills of Berkeley Ca.
Thank you in advance for any help you can provide.