I took a photo of a bantam cockerel recently (see below),
and am not sure what breed it is?
Is it a Belgian d'Uccle?
Any help would be very much appreciated.
No, Belgium d'Uccles have beards and muffs, and do not come in a similar variety to yours. It is a Cochin bantam, though I'm unsure of the variety. Probably a mixed Cochin bantam, or perhaps a very bad-quality Golden-laced Cochin bantam.