Hi Bridget, I haven't looked on this site for a while, so was very interested to see your message. The name of your grandfather was immediately recognisable to me, and it would be great to get some more information, if you have any.
I've heard this story of 3 brothers emigrating from Cleobury Mortimer in Shropshire to New Zealand before, but you are the first contact I've had.
Your side of the family (I'm pretty sure we are distantly related) is expansive!!
The only information on your grandfather that I have, is that he married Elizabeth Verbena Davidson, and his father was Cyril Redwood Dallow who died in Christchurch. Does this make any sense?