welcome to the site.
There are a few on here from the Derby area who should be able to point you in the right direction.
This is the time of year to be making the changes to your loft/aviary ready to breed and house some birds for next year.
I have a pair of youngsters here from there that had been purchased by somebody else for stock and they are 1st class. Also some more on there way.
He has spent a fortune on his birds, have a look at his web site.
between 10 and 21oz!
If I was basketing and put the 1st bird in weighing 21oz and the next was half its weight, it wouldn't be going as I would feel it wasn't in the right condition to race.