Who are these Hagan triplets? (part 1)

One of the topics that came up at a family reunion this weekend was that John Gerald (Jerry) Hagan had a twin who died as an infant.  Interesting fact - I believe that there were actually triplets!  Here's the story:

John Van Hagan (1875 - 1911) married Mabel Deal (1880-1965) in 1899 in Three Rivers, Michigan.

We had always known that their first child was John Gerald Hagan, who was born in 1902.  Jerry, as he was known to most people, was my grandfather's brother.  Below is a copy of his actual birth record from St. Joseph County Michigan. 

The text says John G Hagan, born Sept 15, 1902 in Three Rivers.

An interesting bit of information came up.  I found a letter among my grandfather's papers.  Basically, it is a letter from William Hagan (John Van Hagan's uncle in New York) to John living in Three Rivers.  It's dated July 28, 1903.  William congratulates John on the birth of his "triplets". 

Here is the text of the letter:
 New York, July 28th, 1903
Dear John:
Your triplets picture arrived all right.
They are fine looking boys, very much alike, altho, I think I like the one on the right the best.
The middle one is very cunning.
Their mother will have her hands full in bringing them up.  I don't believe she will be able to tell them apart, unless she dresses them differently.
One you call John, one Gerald, and what is the third ones name?
Congratulating you both on the large increase to the population of "Thrivers" (Three RIvers).
Affectionately yours,
Wm. Hagan

You'll see he refers to the triplets as one is called John, one is called Gerald and what is the name of the third one?   There is no indication that there were triplets - not in the official birth records of St. Joseph County Michigan.  The triplets couldn't have died at birth - because obviously a picture was taken of the triplets and sent to his uncle in New York.

Another interesting note is that the letter is dated July 28, 1903, which would be 10 months after their birth.  But there is no documentation that I can find whatsoever about triplets - not in official records or any family records, except the letter above.

For more detailed information on this family, please click here: John Van Hagan