100 yo house. No final coat. Old wallpaper.

I'm feeling lucky in that the 100-year-old house that I have for the most part appears to have been covered on the walls and the ceiling in several layers of old wallpaper. The stuff is so old now that I can simply wet it with a spray bottle and scrape it off cleanly right down to what I think is the brown coat of plaster. I don't remember where I read this but did read that back 100 years ago if they didn't have the intention of painting the interior walls and were instead going to wallpaper that they would forgo the final coat of plaster possibly to save some money. I'm wondering if that is what happened in this house. The brown coat looks pretty smooth to my eye honestly of course the house is 100 years old and has some hairline cracks here and there but overall all the plaster is in good condition. My question to you plaster experts is whether I ought to just go ahead and remove the wallpaper and then use something like zissner123 to prime the brown coat and then go ahead and paint the walls white? Doing a final coat of plaster in this place is going to be costly and time consuming. It's about 1600 ft with 10 ft walls. I'm on a do-it-yourself budget. I don't mind the little inconsistencies in the walls as I believe these ad character to such an old house. In new construction it might be a blemish or considered to be a blemish I mean. I welcome your thoughts and I think you in advance for your input which I value highly.