I was able to get an appointment to get my broken nail fixed on Monday afternoon. The remains of the gel was buffed off so that the remains of the acrylic could be soaked off. A plastic false tip was glued on, then the acrylic and gel re-done, along with 2 coats of the same gold polish as I already had on the rest and a top coat.
The net result is that unless you look at the underside of the repaired nail, you can't tell the difference between it and the rest, so they're back to looking like they did on Saturday.
Which of course puts me back to having all of my nails quite long and painted a rather obvious shade of gold. Having had no comment or even any obvious sign of anybody paying undue attention to my nails while in boy mode, I've decided to leave them this colour until I feel like a change, or my next infill in 2 weeks time, whichever comes first. :)