I'm a bit of a HT aficionado - I have three: a dogtooth vintage from the 1960s, a green one and a rust brown one. I also have a grey herringbone overcoat that I was lucky enough to be given in virtually brand-new condition: a friend had bought it in a Spring sale, worn it about twice, then put it away for the Summer. Come Autumn, he had put on quite bit of weight, so......he gave it to me, and you know what? It is a perfect fit!
I have a Harris Tweed overcoat (Green brown yellow; originally made for Burton) made on 06.03.1959; 56 years old and still looks good. Picked it up for £20 many years ago and still comes out every winter. Have been stopped in London, by someone asking where they could get one from.