no repros of any part of the original heater boxes that I know of, it's the cores that everyone usually needs, you might end up having to fabricate something .... good luck with it
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics