Thanks, John and Tim.
But I will let the project sleep in the box.
Besides, some people were not glad at all that the truth was discovered. (Like ... the Condon family, even threatening me.)
By the way, finding out that the man in the grave is not John Condon really was a piece of cake. I was perplex that no one had ever found out. (The case is very simple : the man buried in Poelcapelle Cemetery had been found near Railway Wood, and was Royal Irish Rifles. John Condon never was nearby, but had died some weeks before near Mouse Trap Farm (2 miles away, along the front line too), but did have indeed the same number 6322. However : John Condon was R.I. (Royal Irish Regiment). So when the remains were found near Railway Wood, someone must have thought : "R.I.R. 6322 ? Let me have a look ... That must be a certain John Condon, Royal Irish Regiment 6322". But one letter made all the difference : R.I.R. is Royal Irish Rifles, never Royal Irish Regiment (which mostly is R.I. or R.I. Reg. or Rgt.)
Finding out about the age was even simpler : asking for a certificate in the town where John Condon was born, Waterford.
But the most difficult part as I said was trying to find out if the man in the grave (Patrick Fitzsimmons, from Belfast) had descendants or relatives still among us. Sending over 50 letters to Belfast to people named Fitzsimmons (asking : could you possible be related ?) did not help. Only one or two (!) replied : "Sorry, negative, not related." Afterwards someone told me : "I'm not surprised that 48 or so preferred not to reply, not even with a simple e-mail ... This is Belfast, you know ..."
Anyway I am "glad" (how do you spell "glad" with irony ?) that the truth came out ...