Outstanding work Kiwi bloke! Thanks very much guys. I will pick up the research from here and see where I get. Hoping to find some mention of the rifle and the Captain's exploits with it.

@Rino - I have the same issue as Ahmed577 posting photos. Also, need to take some better ones. Like most of my stuff, the rigbys are not pristine. The .275 has a slightly swept bolt handle which is less appealing than the straight ones. It may have been ordered that way, but no indication in the certificate. The .350 is an early SSB, but the bridge has been drilled for a scope mount (not present). The .416 is the most original of the lot, very early SSB mag action - unmolested. Bores on all three are good, but not excellent.