Is it okay to a place vinyl wallcovering over an existing layer of paper wallpaper? Actually, I'm not really sure the wall has wall paper. It seems like it's plaster (irregular, hard surface) which has been painted, and I cannot find any seams or wallpaper butt joints; but, while masking around door moulding, I noticed that some paper would peel away when I pulled the tape off to reposition it. Maybe that was the surface layer of wallboard, but this house was built in 1936 and has lath and plaster throughout. So, even if it is wallboard or old wallpaper, is there any harm in simply filling in and smoothing over the slight peeled areas with joint compound or spackle, sealing the walls with a good prep compound like Zinser's, and laying on the new wallcovering/ I am concerned that mold or something like that will form and cause the new wallcovering to separate and fall off. Any comments or ideas? Thank you.