just going by looks, I'd say it was built in the 80's, the graphic EQ probably is pretty lame and I'd say the board is worth $50-100 tops. Looks like a Teac "live board" offshoot.
I ended up getting the same board you have pictured. I just received it today and I wont be able to test it out until the weekend. What I can say is that everything feels really solid and well put together. Also, I contacted Audio-Technica and was able to get a scan of the original brochure which has some tech info on it.