My post on The Oldest GMs picked up two comments, both related to my remark about 'honorary GMs'. The remark, which was almost an afterthought, came from checking one name on the list, Elmars Zemgalis, whose Wikipedia entry Elmars Zemgalis mentions, 'Zemgalis was awarded the Honorary Grandmaster title by FIDE in 2003.' From that I learned that there are such things as honorary GM titles.
F commented, 'How about the oldest players to receive a non-honorary title?', while ChessNovice wrote, 'If Maróczy and Mieses are held to have only been honorary GMs. Could the same be said for [other inactive players awarded titles in 1950]?'
The answer to F's question would require some work comparing game databases to years the titles were awarded. Determining which players were active at the time they received their titles would eliminate many candidates. The answer to ChessNovice's question is an opinion. As I pointed out in Elo's Untitled GMs, FIDE's first bulk award of retroactive titles was limited to players living in 1950. Even then, the world federation overlooked Sultan Khan. The process appears to have been too subjective to be reliable. That makes all informed opinions equally valuable.
In An important historical review on susanpolgar.blogspot.com, Mark Weeks' Blog was listed as a source. As far as I can tell, this is a reference to a post titled Resources for Historical Ratings, which pointed to a resource on chess.eusa.ed.ac.uk. The post on the susanpolgar blog extracted data from that resource. A comment by chesss44 points out that Keres' 1970 rating is wrong ('a major error') and goes on to mention several other rating errors.
It's great to see so much interest in historical chess ratings, but I prefer to keep a balanced perspective. Lists of top-10 players from the past are of minor importance. Typos etc. on the same lists aren't major errors.
In a thread on the Letsplaychess.com forum, Chess video requests, Comte de MonteCristo questions a comment on my page 1985 Kasparov - Karpov Title Match : Highlights. This is worth a post in itself and I'll came back to it later.