Hi Les
I'm doing the same thing at the moment so can help here.
First I strongly advise modifying the Panzer IV tracks while they are still on the sprue. I didn't and have had a lot of extra hassle as a result

It's simply a matter of removing the ice cleats from the bar across the link and scribing a line along the length of the bar.
There aren't quite enough links in one set to do the job either. Not a problem for me as I'm doing an Ausf D and E using the Battalion Bits conversion and WW2 Productions track.
The drive sprocket is the biggest problem as the 15.5" tracks had a different pitch. So either add the Panzer IV teeth to the Cromwell sprocket or file the teeth away where the track contacts the Cromwell sprocket. I'm deciding what to do on this one at the moment.
HTH and good luck.
BTW Thanks for the staff car MDC wheel hint. That's back on the build list again.