Thanks for your thoughts about the 'Cover' paper, didn't know about the 20min soak time. Been soaking for 5 mins, will try out the longer time.
I have a RGM2642 table top etching press and you're right, there's not alot of info on them, I had to experiment with mine. The website below are the makers, I'm sure they would answer queries.
I mostly use my larger floor model Urbino model for etching and collographs or hand burnish finer papers on woodblocks.....but I do sometimes use the RGM and it is a lovely little machine!...do buy an extra blanket or cut one or two out of an old bed blanket. I use a 'blanket' of thin, fine, dense foam as a top blanket at times to help with traction on the top roller.
It can slip sometimes with metal or plastic plates and finer papers so you do have to play with calibration and blankets but the process is very do-able. For lino, blue/green vinyl blocks and low relief collographs it works very well, high relief collographs not as well, do need heavier rollers for those.
If you use it please post a photo of your work!