Thank you both for the advice. I had a chance to run a test roll of film throught the 67 today. I can see why people like the camera, it has a great feel.
I will definitely negotiate with the seller to get a better price to include repairs on the 67 I'm looking at or wait to find a 670 in better shape. The W67 looks like an awesome camera as well.
Other questions: does the 670 have any improvements to the viewfinder/rangefinder over the 67? Does the W67 have the updated features of the 670, such as the double stroke winder and double locking back?