OK, on my StuG IIIB (Tamiya) I decided the kit vinyls weren't going to cut it, so I decided to swap them out for some 40cm Dragon Magic Tracks, of which I had two extra sets.
Good news: They fit great, no modification of the idler or drive sprockets.
Bad news: Since I was planning on using the kit tracks, the road wheels and return rollers are glued in place and I need a way to separate the indy tracks when dry to paint/wash/etc. Here is how I'm sitting right now:
I think this would be the best place to separate them, as the road wheels and return rollers are glued in place, and I can mate up the tracks on the idler easily enough, and the drive sprocket is a tight fit, which means if I don't have a way to glue it down, friction should be enough to hold it in place, then I can hit it with a little CA if necessary.
Any recommendations would be helpful. Oh, and the other side just has the bottom run completed, as seen in the foreground of the second photo.