Hey, KK, first off, I know it's a bummer buying something only to find out it has silly broken parts that had no reason to be broken...what exactly is broken off on the fender?
I attached 2 old pics that show the fender nut, screw and tab locations. If it's only the 2 forward tabs you're still ok...(not sure how they could break those off?)...it still has 1 screw on each side and the 2 nuts in back. Even the side screws probably arent' completely necessary? It's really the 2 nuts in back that do all the work.
Again, I know the scoot is in good hands and you'll get it all put back together the way it should be.