It was Richard Knotel that I had in mind although perhaps Herbert cannot be disregarded. Although Richard built-up a carefully compiled data-base of source material, he did rely on a very wide range of correspondents from all over Europe to supply much of his information - even Percy Sumner from Britain and some from the USA were in the net. Inevitably some of these were more accurate than others; possibly including Cenni from Italy whose considerable work has come in for some criticism.
Fortunately research still moves on and I do not think that the excellent work of Guy Dempsey has lacked recognition on the subject. The same could be said of Thomas Hemman whose recent publications have cast light on little-known areas.