I have finally received a clarification from Foma, via B&H, via their buyer, regarding the luster surface mentioned in my original post in this thread.
The surface is 132 and comes on Fomatone Classic FB, the warm-tone stock, even though the label calls it "Matte", or "Matt," which is the same designation given to Foma's actual (flat) matte surface, which comes on its neutral-tone Variant 112.
I did not receive any clarification on what Foma's advertised "Fine Grain" surface is. Anyway, to paraphrase Shakespeare, "Wherefore art thou Matte? ... A beautiful lustre surface by any other name..."