As a potential buyer, I can create a short hand search feature that permits me to, with one click, search for certain designers and manufacturers. I can limit that search to catergories and sizes. For example, I could have a "favorites" search for 16.5 dress shirts limited to Borrelli, Truzzi, Finnamore, Charvet, and Hilditch. The search engine would then pull up all the shirts meeting those criteria and none other.
The pp seems to be saying that when he constructed a search for shoes that included among the manufacturers Martegani and ran the search, your listings did not appear. I have seen that occur with other sellers for other brands. As to how to fix that, one of the many ebay sellers on this board may have suggestions.