REMlogic is actually not that old, as it was the offshoot of the merging of REMbrandt with Somoligica. Medcare held a meeting in Boulder CO. for some longterm users of both REMbrandt and Somnologica to come together to help them hash out what features of both might be included in the new product; then not named, but eventually becoming known as REMlogic.
My point being, that REMlogic was written in at least the early naughts, with fairly recent hardware designs, while REMBRANDT is a Windows 95 holdover. NOW, if you wanted to run that, that might be problematic. The REMlogic opening dialog box always bothered me and is confusing as hell.
I do have an official Natus REMlogic 3.4.3 CD iso to offer. If desired I will upload ISO to my google drive. I also have a copied REMBRANDT 7.5 disk.
What I will request is that whichever version one chooses, they use the z-ratio add-in Medcare wrote for me, which should work in either platforms.
http://www.z-eeg.com