Information on a Columbia Masterwork Record Player?

I bought this Masterwork m1801, 4 speed (78,33,45 & 16rpm) record player a few days again from a barn sale. I would love any info on the year. The only thing I could find was a model number on the back and a small paper saying the needles were replaced in 1969. I looked all over the internet and cannot find anything with the trade stamp this one has inside the cover.

Thank you so very much.