"There's also D&D, on 121.5. They're not just there for emergencies. Indeed, given that they would untimately been invovled if Shoreham had started overdue action on Gengis, they'd probably appreciate the call to let Shoreham know."
Absolutely NOT! Do NOT under ANY circumstances make such a call on 121.5 unless urgency or distress dictates otherwise. The information should have been relayed back to Shoreham via landline -and it was hardly critical in any case.
I use the radio when I need to and obtain the class of service appropriate. If I'm going within a few miles of an aerodrome, I'd probably give that aerodrome a call, however.
The Golf Alfa Good Mornings who clutter up the RT with non-essential RT yak (often including their life history) are irritating beyond belief for both pilots and controllers alike!
Always ask yourself whether your actually NEED to make that call!