Welcome back David
Haven't seen a curling stone since I accidently rolled one of my grandfather's stones on to my foot aon a visit to Scotland. Found your location on a map. Coffs Harbour should be easier. Not curling country - we grow bananas here - no frosts. Lots of dry sunny days - lots of rain when it rains. Had a dry spell this summer followed by 12" (pre-decimal inches over two days). We had 26" over two days a few years ago - but that was extraordinary and it flooded.
Hope you can throw some light on the location of the Caldwell farms. Seems to me that they were concentrated, but not exclusively south of the Irvine ie: Kyle Stewart. Checking on the Fullarton sites - this seems to parallel their family locations. Even to the extent that the Fullarton's extended to Dreghorn and crossed the Irvine near Kilmarnock. The Fullarton's were close to the Stewarts even before they were kings. It ws a Sir Adam Fullarton who granted Gaylis (Gailes) to Petri Caldwell in 1391.

The Todriggs/Annanhill mob seem to have had connections to the Rye Burn valley running north west out of Dalry and further towards Largs. This almost seems to be a Mure/Montgomery connection and may be the joining hand between Ayrshire and Renfrew.

I value your input as being more recent and more relevant than mine which is just childhood memories and parent's story's.

Notice the complete dearth of native, currently resident, Scots & Irish Caldwell's on the site. One needs to be away to appreciate it! ... but I wouldn't go back to live there for quids. (No offence meant).