Should have added that Bentley kindly helped me source NOS clamps from Mock Auto some years back. And as others mentioned, many vendors sell the reproduction tower clamps, but they are thinner metal than the 'original' Wittek clamps, and (at best) you only get one chance at tightening them properly on the hose. Best to look out for dated or even undated NOS items, which appear identical to, and install like, dated take-offs.