Gentlemen -- I see you are all in accord to dress in the best attire you have available.
Varley -- Falling down suit will be fine. Tmac, if you can paint a bow tie on your (almost?) white boiler suit with some Bunker C that will be quite acceptable. Farmer John, your Dickie sounds a bit like mine -- easy to roll up (even though it's shrunk quite a bit) -- just a matter of finding it first. Engine Serang, the cummerbund will be fine as long as you wear it high enough to cover the matted hair on your chest, only too readily visible not having a Dickie. Methinks Sir William is bragging a bit about the stiffness of his Dickie. Drinks all round.