No leads yet?
Is this trim piece specific for right/left, or is it mountable for either fender? It looks like it is symmetrical and would go on either side.
I suppose, if none can be found, you could use the current one as a model to have someone fabricate a duplicate. Although the cost would be ridiculous.
It looks like a part that you should be able to find somewhere, but may need to be chromed.
Certainly not a show-stopper for continuing the restoration in the meantime.