WTB: Door lock mechanism (LHD, Left) for 1970 911 T

Hi,
My driver's side (Left) door lock mechanism has worn out. I optimistically thought I could replace the worm parts but have now decided it will be simpler just to replace it. I've been looking at a few threads on this subject.

It seems that these guys: http://www.mittelmotor.de/webshop/englisch/mm.htm only quote 1 part for years 65-93 - This part number "1,83133A new"

The Porsche PET shows this one:
911 531 053 02. This one has the remark "/L -72". According to the PET legend this is for a LHD drive car, left hand side.

Looking at this thread though, it doesn't look as simple as I was hoping. Any advise?
http://www.early911sregistry.org/for...ck+replacement

Of course, if anyone has one they don't need I'd be interested in buying it.

Many thanks