Hi B,goodman,
Just a quick thought, if george converted to being a catholic so he could marry mary , perhaps he had to take a catholic name hence that could be where Joseph comes in. It stands to reason that when he had his own son that the child was given the same name as was tradition in those times.
I hope you have some success with the death certificate, it will be interesting to see who reported the death, you never know it maybe george or mary, that would be a good one to connect them together.
Look forward to seeing you soon,
regards, Jackie.