I have an assortment of old ones, including some NOS by REG that have very good chrome (PM me).
IIRC there were some made for OS tubing from Shimano (DuraAce) that are extremely rare, otherwise I think one size fits all vintage bikes with standard diameter top tubes (or do you French fans know differerent?)
There are also some that simply use their spring action (instead of screws) to clamp the housing onto the tube, some really cheap and nasty, but there are some old British ones that are well finished and have great chrome.