Found OBHS Register - I think it only helps in a negative way
Dates are entrance year - around age 13
Let me know if you want any details from the body Most entries provide a "current" address and occupation also date and place of death where known
These are all the Hendersons up to 1938
Otago Boys' High School
Old Boy's Register 1863 - 1938 inclusive
Published Dunedin 1953
Index P 342 column 1 (scanned with quick check)
Hende. Keith B. 1942
Henderson, Allan 1923
Henderson, Allen J. M. 1931
Henderson, Angus 1903
Henderson, Art. J. 1915
Henderson, Bruce K. 1931
Henderson, Chas. S. 1928
Henderson, C. B. 1929
Henderson, C. S. 1933
Henderson, David R. 1926
Henderson, Eric C. 1924
Henderson, F. McG. 1917
Henderson, Fred. C. 1924
Henderson: Fred. I. 1944
Henderson, Geo. 1934
Henderson, Geo. A. 1917
Henderson, Geo. A. 1884
Henderson, Graeme 1943
Henderson, Herbt. 1891
Henderson, Hunter, 1898
Henderson, Hugh R. 1916
Henderson, Hugh W. 1934
Henderson, Ian A. 1938
Henderson, Jas. 1863
Henderson, Jas. 1902
Henderson, Jas. A. 1916
Henderson, Jas. G. 1927
Henderson, Jno. 1894
Henderson, Jno. H. 1947
Henderson, Jno. R. 1924
Henderson, Jno. S. 1906
Henderson, Jos. W. 1924
Henderson, Kevin H. 1946
Henderson, M. C. 1887
Henderson, M. R. 1932
Henderson, N. D. 1926
Henderson, Robt. B. 1912
Henderson, Robt. H. 1917
Henderson, Robt. R. 1926
Henderson, Ross S. 1941
Henderson, Wm. 1863
Henderson, Wm. 1879
Henderson, Wm. E. 1926
Henderson, Wm. J. 1891
Henderson, Wm. J. 1915
Hendra, Henry N. 1926