Great pic on the puckstruck.com site:
"Hometime: Black Hawk left winger Johnny Gottselig poses with Chicago’s new centre-ice Bulova clock before it’s raised to the Stadium rafters in 1943."
https://puckstruck.files.wordpress.com/2015/06/chicago-clock.jpeg
Great pic
OK being old (65) I have seen most of these clocks in person.
I saw the Bulova clocks at Boston Garden, Boston Arena (one sided version), Rhode Island Auditorium, Chicago Stadium and Memorial Auditorium in Buffalo. (Detroit I only saw on TV) and I saw the Forum SporTimer at a box lacrosse game in the summer of 1965.
I also saw with my own eyes the first digital scoreboard in the NHL which was at Madison Square Garden III but it was on the facade of the balcony on both sides.