A trug would work but I use a strip of hession sacking, I wrap it around the bird then the hook of the scales works like a clip to keep it closed.
My mate ended up taking 2 cockerels and 3 hens, he's going to set up 2 breeding pens one with some nice LS hens I sorted him out with last year.
I might get a few IG x LS hens from him next year to blend into my PG table bird project.
Really interested to see what your birds dress out like and how the crosses compare to the pure breeds in size, shape and taste