Hello Longhitv,
I'm Swiss, but I do not know Mr. Marco Marinello (his shop is in Zürich). The parts you mention were for sales on his web site (
www.elevenparts.com), but btw, seems to have been sold now !
I would tend to say that you can fully trust Mr. Marinello, he is known to be more than a very serious Porsche "Intelligence" person ! One of his very well known area of expertise is anything about the "356's".
For example, about the 356, this is HIM, ..that closed the discussions about the 21th 356 GTL Abarth, by writing a paper that mentioned that the chassis #021 was NOT a GTL Abarth but an hybrid, i.e.: a 356A body ..that was installed (by the factory) on a 356B chassis !
(For those that are interested, I think after years of searches, he even located that "crazy" 356 with the chassis "#021" !!)
Good continuation and all the best for your tribute to a "R" project.