When was this microscope made?????????

I have a vintage Selsi Microscope Kit. The booklet looks a bit retro-ish. I just wanted to know if anybody could find out when this was made? What year did this kit come out? It's old as heck but looks so cool. Sorry if this is the wrong category, I'm only going by what Y/A! suggested since I have no idea where to ask this. Thank you!