I found a great map.
University of Texas. ww2 era maps of eastern europe.
The actual neck is a bit too big to recreate in a scenario.
Perekop is just ahead of the first ditch. On the east side of the neck.
Theres another ditch just a few clicks behind it that only goes halfway in from the west side.
A road, and a rail line, both cross the ditch.
A warm "thankyou" and a round of beers for Kingfish, Erwin, and Cuirassier.
Any and all further info is also appreciated