Hi Paul,
what you need to look for is the Catholic Directory for the Archdioces in which Oldham falls, for any year when your gguncle was likely to be there (I think that they are published annually).
It would be expected to list all the parishes, churches, mass centres, schools, etc. and also have a list of all the clergy. The list of clergy may give details of date of ordination and perhaps where they studied.
If there is an archdiocesan archives, they may have copies of the old directories even if they do not keep parish registers there.
By comparing directories from different years you could also build up a record of which parishes he was in at different times, if he was moved around.
As Very Reverend Canon, I think that he would have held a position with respect to the Cathedral and may also have held offices such as Rural Dean or other special positions, in addition to being parish priest. These would also be listed in the catholic directory for the corresponding year(s).
If you have his death certificate and so a precise date of death, you could also look for a possibly quite detailed obituary in the newspapers, including catholic newspapers. Prayer cards would probably have been printed and distributed at the burial service and sent to relatives too and may have some details of his life on them too.
