Where is the best place to sell?

Hi.
I am just doing some research on behalf of a friend who is not very familiar
with the internet, but is a collector of model engines. I am equally
unfamiliar in his field, but I know he has a new engine and carriage that he
wants to sell (I think it's 5" gauge, if that makes sense). I have tried
looking at EBay for him to sell on, but they have a £100 reserve charge for
items over £5k so he doesn't want that. Can anyone advice him where the best
place to sell is? Or are there any active websites that offer a selling
service?
Many thanks,
Rob.