Originally Posted by
Road Fan
It sounds like you are mostly on track in your thinking. Why do you need a 130 mm wheel? Is the rear dropout spacing 130mm? If not, 126 (sometimes 128) is the norm for 7-speed freewheels, and good used126 wheels are usually pretty cheap on Ebay.
I measured the rear axle on the stock wheels and it measures out to 130 so it only makes sense to replace it with one the same size.