I hope that this is the right place for this kind of question but if admin thinks that it should be in Racing collectibles, please be free to move it there. I'm posting this here because no one is trying to sell anything, just to learn something.
A friend recently purchased correspondence of late Zlatko Živković, late Croatian motorsport journalist. It consists of around 300 letters from different manufacturers and clubs all around the world to him, dating from 1947. to approximately 1980. Mostly there are the answers to various questions asked by him and sent along with brochures and photos. So far I went just through maybe 30% of it (sorry, didn't want to be impolite and ask friend to let me take a photo of it so can't prove any photo evidence - but if needed I'm sure it could be provided, to some reasonable extent). I sincerely doubt that it will give any new insight to mysteries of the racing world but there were some gems anyway in the part I checked so far.
For example, I saw a letter that could bring completely new light to events of 1955. An official one from Lancia, stating that they can't provide any details about their F1 car as they transferred everything to Ferrari. Great thing is that it is dated 13th January 1955! However (and indirectly confirmed in another letter from same factory) it is an obvious case of typo. So early in a new year it is not uncommon for anyone to erroneously type the previous year instead, so it is obvious that letter was actually written in January 1956.
I also liked pars like FIA confirming disregard of jet engines in terms of LSR, as they have "no practical value", ACO denying to say anything in 1957. about two years earlier accident, as the legal procedures were still ongoing, Raymond Mays explaining his racing exploits and denying any government backup to BRM and some more details. BMW denying plans to build a sports car or enter any racing activities in 1952. was also nice - and I was also a bit surprised to see that they were already referring to 1940. GP di Brescia as "Mille Miglia" back then...
However, my questions here are about the signatures on letters. I'm quite sure that Enzo Ferrari didn't personally signed the answers to some Yugoslavian journalist back in 1956., even if the correct violet-purple ink is present. It goes for Orsi signature on Maserati letters too, and I can presume that Stirling Moss was so popular in 1959. that he also hired someone to sign his letters. But there are some other names that I thought to ask, maybe someone knows if they signed their letters personally or they let the secretaries to do it for them? I know we can't really judge it without visual examples but let me ask anyway. Letters I saw by Raymond Mays have so great personal touch that I somehow believe that he really signed them. Also, HWM was probably so short on employees that John Heath might personally sign the letters. Also there's a Lotus letter from 1959. signed by sales manager P. Warr...
Letters are not for sale and I don't see any changes in foreseeable future but I'd like to determine - not the originality, because it is really obvious that they are original - but possibility that some of great names from racing history personally signed some of them. Don't know much of the way how it was done at those days and how probable it is. Your thoughts, please.