The following occurs in Kingsley's "Roses and Rose Growing", 1908, now available online: … while Mr. Orpen, of Colchester, introduced the beautiful [Damask] pink climber, Mrs. O. G. Orpen, in 1906.
Speargrass's "Single and Semi-single Roses" in the Adelaide "Mail", 12 April 1919 lists 'Mrs. O. G. Orpen' (O.G. Orpen 1916) …

So he was O. G. Orpen and came from Colchester. The rose named after his wife was sold through Cants of Colchester, naturally.