Hi Rick,
My right internal fender (280SL1970) had no holes and was original because it was good spot welded as original.(see the picture in appendix, even with the big structure unwelded, you don't see the holes which are supposed to go in this big strcuture to alow the lubricant to go for corrosion prevention).
I don't now exactly when they stop to make holes.
When I ordered one brand new inner fender in MB, the one I received was with holes.
I hope this will help.
Best regards.
VincentR