The other thing is that the existing linoleom has a burlap backing.  I believe this was standard in the olden days; worked as reinforcement. Could
this be original? I would say so. It lies ove a unremarkable face nailed T&G floor, which now people like this old subfloor. Yeah, well, there are also the jerks who tear ornamental plaster off common brick; onee would hope it's don less nowadays than it used to be, but most of the real stuff has probably been "adaptively reused" away by now. These are among the wonders of the modern world-- stuff They thought was shit, We think is gold.Someday we will be clear coating fiberboard.  I tried varnishing particleboard for use as kitchen countertops in my kitchen in Joisey City.  It looked OK initially, but I have a feeling it may not have done so well once it got wet. Anyway, wanted to see if this could be original as well.  Yeah, it just wasn't meant to be exposed, or at least not to be exposed to polite society.

And remember, if you are going to shoot your hand with a nail gun, be sure
that the nails are stainless steel. I should think it would be be better not to shoot oneself with a regular gun nail than to shoot it with a stainless nail, but that's just my personal opinion. Others may disagree. Less infection.