When it comes to Gerald Gilman (1892/1893-2004), he's validated as born in 1893, and 1893 is supposed by his 1900 US Census and all subsequent documents. However, there is a birth record for a Mazel G. Gilman, female, with Gerald's exact date of birth, but only for 1892. Gerald Gilman's parents are listed as having 1 child in total and 1 living child in both the 1900 and 1910 US Censuses.

I checked and Mazel can be used as a very rare male name as well. Just try doing a search for it on Find-A-Grave, for instance. Maybe he was initially named Mazel Gerald and switched to Gerald by 1900 due to Mazel's sheer rarity? And that the F (for female) on his birth record is simply a typo/mistake?

If Gerald Gilman's parents had an extra child who was either stillborn or died at birth, then surely a death record would exist for this extra child and surely a separate birth record would then exist for Gerald himself from the following year, and yet we see neither of these two things! Which suggests that Mazel G. Gilman really was Gerald and that the F on his birth record is indeed a typo.

But if his birth record mistakenly got his sex wrong, could it have also mistakenly got his year of birth wrong? Can 1893 indeed be correct even though the birth record says 1892? FWIW, I don't think that the birth record itself is specifically from 1892, but merely from the early 1890s--though this can be checked.

What do you think, @Fish @Mendocino? Should the GRG and LQ upgrade Gerald Gilman's validated age by a year? From 110y,246d to 111y,246d?

@futurist The birth record appears to be a birth index and it doesn't seem likely that it's from 1893 to me. 

It's clearly marked that the 30 Apr date is in the 1892 year, but perhaps they made a mistake? Possible, but in the surrounding pages, there is not a single example of any birth recorded past March 1893 - only January - March 1893. I've noticed that often times these birth index books do not go on a calendar year, but at the top state they are recording births from say "May 1903-May 1904", which seems to be the case here. So unless when that child was born a year later in 1893, they decided to go back in the wrong page and record it there, it's not likely to me. 

So, his age should be upgraded by one year?