Spotted...

It was a bit dark, could well have been, rider was late 20s early 30s short hair and stubble, seemed cheery enough. (I'm similar description with longer hair.)

Maybe not me then - I generally wear a helmet so can't see my hair! If you see a mid-20s dude on a red frame/blue fork single speed give me a wave/shout. I hardly ever see fg/ss round this way...