most keyboards have a shift key - lower case is easier to read if you cannot use it - if necessary type out you message in notepad + go back and edit capitals before pasting into message board.
When I say 'would appear to have' I mean that names match and there is other linking information - usually wills - the marriage registers at this period (in fact not until 1849) do not identify the parents of the parties - for Wm Bridson + Alice the additional link is the linkage between the two husbands of Patrick's daughters - at the time I made a summary I was only interested in it as a means of possible identification as well as distinguishing between other Wm Bridsons - I have done very little on Malew but would expect William to have a will though possibly in early 19th C where I have done very little.
Where did your 'foster' children come from - in fact where did your 'facts' come from if as I understand it you have not personally seen the missing bible - I've seen many trees linked merely by names without checking for burials or land holdings etc (eg in Malew IGI there are supposed mothers names who had been buried for 20 years - the submitter had not checked for second marriages). To make a suggestion possibly a researcher just identified Patrick as the only Pat Cain in the IGI with a baptism in 1712 - after that you can trace forward a generation.
However I don't understand your foster children is this from Manx records or from your American records - in Manx records such are carefully indicated as they have property rights. Patrick records are not easy to work with - the register start late (they are physically a mess with many entries unreadable - the IGI has misread or misunderstood the year headings thus many baptisms are out by a year - I checked my reading against actual register in places or bishops transcripts which were done on a per year basis) - I've only just started work on land records + wills in detail - against your John Cain is the only indication kionslieu which is the only time I see it against a Cain name
What MARGERET CAIN, BORN 1740 IN KK BALLAUGH - - are you possibly working from the IGI ? - I have no such entry in my own transcription - Ballaugh in the IGI is full of junk I'm afraid - years,dates + parishes misread - there are a whole group of what appear to me as purely conjectural entries that are not in the register - nor for those years I checked in Bishops transcripts
However one draw back - there is family to Wm Bridson + Alice Cain in Malew (they married Malew 17730613) 4 children between 1775 + 1784 before a record of Alice's burial in Malew in August 1785