What is a good starting point for the amount of Jagdpanther Magic Tracks to use for each run.

I don't have the DS tracks to count or measure against.

Real Panthers and Jagdpanthers had 86 links per side.

Thanks

Another method is to wrap a strip of paper around the complete suspension (include sag et.c) and use it as a simple tape measure. Mark the correct length and lay the track on the paper strip to check.
/ Robin

Don't forget when installing the idler arm you can have it in a few positions if you understand what I mean.

Yes,thanks to both of you.

I would not go exclusively with the actual track link count on the prototype vehicle. If the dimensions from the sprocket to the return idler and the dimensions of the track links are not EXACTLY to scale, the length may not be correct.

Robin's method is a very good way to get a proper length and then build to that.