hmm....honestly I don't tink, because if I would have token the tileset from your rombase the a clean rom it would be exactly the same as is I continued working on your rom base ^^
but maybe I took a few tiles like the ground your right ;)
if not I wanted to have in my rom everything done by me, the day when I'll make a better ground tile, rock tiles and so on I'll remplace them.....
I use these ones just because I myself havn't done all tiles yet ^^