I just took a look at the migi shell in auction 120368518103 (your picture 2) and compared the cuts to those on my Duchess. The Migi modification definitely cut away more of the metal then was necessary for the Duchess. This would show as a gap between the lower part of the grill shell and the front of the Duchess fenders.
That said, if you can win the Migi grill auction at the right price, you are gettign a shell AND slats in great shape. In the long run, it might be cheaper to buy this, have some weld in small patch panels to match up with what your Duchess needs and have it rechromed. The biggest variable is the chroming cost. I’m not sure what that will run.
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica Roadster
If you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)