Can OS X 10.6.8 Snow Leopard be installed on a 2007 MacBook Intel Core 2 Duo, 1GB
I am running SNL 10.6.8 on a similar 2007 MBP, a little faster than yours (2.6 GHZ).  Original OS was Tiger.  I had initially upgraded to Lion but found it wouldn't run Final Cut Express 4.0 reliably.

Good luck!