This was our solution for the CT 7 Worthington. The idea was to direct 6BK4 heat away from the flyback.
https://visions4netjournal.com/wp-co...A21960C18.jpeg
BTW, the vent cover was retained from the 21CT55 and can be returned to the HV cage with a few grommets and screws, but I known that will never happen.