Chuck,
I just took a closer look at the photos in your gallery. It looks like the turn signals are mounted directly to the fender without a mounting pad.
You need part #281-068 from Moss Motors ($3.80 a pair). It’s #1 in teh diagram at the following site:
http://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexI D=32859
Paul Mossberg
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)