Not necessarily full beam or sleeper sized, but something over 6" by at least 3" and about 1.5 metres (or yards!) + long - for the mantle at least.
Open to anything with some character, bit bashed around or otherwise aged, or what have you, which I can make into a deep-topped mantle which is supported on uprights.
Rough(ish) timber can be smoothed, aim eventually to wax it.
Needs to be dry, unpainted and woodworm (etc) free.
Thanks.