Kristina, if it came to you from Primrose Warburg's garden as Brenda Troyle then I'd leave it labelled as such. The problem is, it's very difficult (often impossible!) to distinguish with any great degree of accuracy between the likes of Brenda Troyle, S. Arnott, Backhouse No. 12 etc. If perfectly grown, healthy, full-sized bulbs, you can perhaps find some small distinguishing differences (or think you can!) but under-performing, smaller. less healthy bulbs of any of them can look virtually identical to ditto bulbs of any of the others. Many a snowdrop grower has been driven to distraction by trying to decide if this or that bulb is Brenda, Arnott or whatever.
The best anyone can do is stick with whatever name they got their bulbs under. If they came from South Hayes, they're as likely to be "correct" as anything else if not more so.
Enjoying the NBGW thread by the way. Fascinating.