Thanks to JAA I've found the tomb of the Penitent Coal Baron. (See Post Here)
Here it is:
Further more he is buried in Merthyr Tydfil rather than Aberdare.
Except for that (and a few other minor embellishments) the story was at least 372% accurate. Wikipedia page on R.T. Crawshay here
My only defence for the errors in my story are excessive quantities of alchohol, a 40 year gap and the fact that it was told to me by a retired and poetically drunk Welsh miner.
But personally I don't consider my error (or the miner's) that bad.
Under the circumstances, I think we both did quite well.