Good morning (evening) Alex,
Fingers crossed something turns up. I can't even identify Robert on the 1841 Census. I was hoping to see where he was living and who with.
If he died after 1855 while living with Isabella you would expect that there
would be a record. Either the name has been misspelled or he died away from home. Or he never died at that time at all. He could have left the family......
Hope you manage to make the journey across "the watter" in 2015. If you are visiting Ayrshire send me a Personal Message - maybe catch you for a coffee

Looby
