Attached Link: http://www.thedarkroom.co.uk/rk2/meopta1.html

Here's a link with info. They seem to have/used to have a 5, 6 and 7. The 5 for 35mm, 6 for 6x6 and the 7 for 6x7. It's the first model. And the only usefull info I can see is the max enlargement with a 50mm, that's larger than A4...so with 80mm A3 would be possible !?