My search didn't turn up anything, but sometimes forum searches aren't 100% accurate.
An older scope alternative to the EMZ-5 could be the Olympus SZ-III. I used one for 25 years and it served me well. I think the Meiji is a bit better, but that old Olympus was a workhorse. It's what McKenzie used as well as a number of other engravers back in the early days of microscope use. If you find a used one be really careful to examine it for that nasty fungus that grows on optics. To my knowledge there's no way to eradicate it and the quality of the image will be seriously degraded.
I too have been using the old Olympus SZ-III, & like Sam says....It's a Workhorse.......Great optics
I think I paid $300 bucks for two of them back in the mid 80s......but that was a special deal.......
I'm Happy with mine...