Hi, Sanj.
Welcome to the forum and all that.
But why on Earth do you want to do this?
Surely there must be perfectly good vehicles in the UK for this purpose?
Even if the shipping cost is not prohibitive, you would constantly be searching for parts and expertise to maintain it.
Are you one of those "amcar" nuts? Do you drive a split-window Corvette or a 1976 Cadillac convertible or a 1965 Mustang? I know a thing or two about that, as I am one of the founders of the Amcar club in Norway, and also started the local Amcar club in Oslo -- all this four decades ago. LOL
One detail: You say "food
trailer". Do you mean to remove the engine and the front axle and turn the bus into a camping caravan style of trailer?
Let's hear some more about your intentions! It's bound to be an interesting story, whatever it is.