I do have a tip for you that I didn't see posted, make sure that the backer plate that holds the film against the slides on the bellows is doing it's job and is still springy, in cameras of that vintage they were sometimes made of Brass and can take a set over time, you may need to just give them a little tug to be sure they are holding the film correctly. That was the biggest ruby window light leak problem I had until I figured it out.

I use the electrical tape window cover as well, I do about 1 and a half turns of the winding key and then look to get the number into place, I also shade the window with my body as well. No problems any more.