Please don't consider my questions to be critical of your superb work.
Not at all
...it's just that these images weren't initially intended for this use - so I'm afraid they are not very customisable.
However, if/when I'm able to do something specifically designed for VTT usage, it's comments like this that will come in really handy for maximising their usage
...however I have no idea if/when I'll eventually start such a project.
Well... since you are taking suggestions, perhaps for a future set "intended" for VTT use, just leave the floor out totally. Since Maptool has several layers, this would allow end users to put in whatever floor texture(or more than one if they want!!!) they wish to use on the background layer, and then put the "walls" over top and arrange as needed. If you provide the "floor" as it's own texture also, then users could do either/or as they need.
Anywhooo.. thanks for the donation!!!