In searching Shellac... and (Lac)quer are finishes made from the a resin excreted from a Lac Beetle or similar bug....
In an effort to make this room as presentable as possible before I sand the floors..
I washed the floors with a light TSP solution... The existing finish seems to be soluble in water.. The finish seems soluble in water... i.e. it wets and I can mop it around