1971 Jackie Stewart Tyrrell suit.
This original complete one-piece suit was worn extensively by Jackie in his Championship year while driving the Tyrrell 003 (Ford Cosworth). As Jackie was quite serious about safety the suit is larger than you would expect for his stature as he wore it over a second uniform underneath. There are several fantastic photos in a variety of books showing Jackie wearing this exact uniform.
When Jackie saw this he was amazed we had it, as very little of his personal gear has gotten out over the years.