Back a generation in Ayrshire?

In a blog on 4 July last I attempted a 'tree reconstruction' of the family or families that existed in Ayrshire in the 17th and 18th Centuries. This includes Robert McIlhago(w) who married Bessie Johnstone. They had four children, first Agnes who probably married a James Gemill and had a daughter Margaret; second Robert who may or may not have married, third Mary and fourth John. I have just been looking closely at the entry for the baptism of Robert which is in a rather difficult 17th Century script and which I now believe reveals to us a fact that we haven't known until now. It reads:

Robert Mcilhague sone lawfull to Robert Mcilhague fisher in Newton of Ayr and Bessie Johnstone his spouse was born on monday May 30.. 1687 and baptised on......day [ ] after wittness Robert gfather and James Gibson.

In my blog on the Ayrshire reconstruction I said that I was uncertain of the name of the father of Robert who married Bessie. Based on naming patterns I suggested it might be John or Robert. I think we can now say with some certainty that it was Robert. Grandson Robert was born in 1687. I estimate that father Robert would have been born about 1660 and that grandfather Robert would have been born about 1635. It was probably his father who was the Robert M'Ilhago who witnessed a charter in Tradidnel in Ayrshire in 1597.