Well, thank you one and all
I think now that I have two courses of action following your advice.
1/ Write to RCB Library hoping an archivist could take a look at the forenames of the groom and give an indication that it could quite possibly be John 'Dixon'.
2/ See if I can order a microfilm via an LDS Centre. In the past, I know that this latter course can take many months but, hey, I've been on this case for almost 20 years, so what's another year....
Having just looked at the churchrecords.irishgenealogy.ie website and put in the surname 'Disor', I get nothing back other than the relevant entry. There are very few DISORs in Ireland anyway. Maybe the person doing the transcribing knew a DISOR or two which coloured their judgement when looking at this entry.
Again, thanks for your responses
Chilis