I would like to use a 6502 to replace a 6507. Will it work?? And if so,
I would have pins 1, 3, 4, 5, 6, 7, 35, 36, 38 to deal with on the 6502.
There are pins 23, 24,25 which are A13, A14, A15 which I assume just
go to ground. Any help would be appreciated.

You'll have to make a pin-out adapter, probably best done with a 28-pin DIP header and a 40-pin socket, using thin wire (like wire-wrap wire) to make the various connections since they're in different orders. Definitely do not connect the address lines to ground. Those are outputs which will go unused.

The 6507 is a 6502 in a 28-pin package.

The silicon is the same for both, only some of the signals are not taken to pins on the 6507.

I used a 6502 when I copied a disk doubler for the Atari 105 disk drive, which normally uses a 6507.

it worked fine.