Are there foam seals inside heater box

[Alexk22]

I'm trying to do what I can to improve the heating and ventilation on my 1961 3.8. I've removed the heater box, freed the flaps (one was rusted solid), and replaced the interior/screen cable. The heater box has obviously been restored at some point. Does anyone know if the original box would have had foam on the frames that the flaps sit on, to make the flaps more effective and less clanky? The various bits of foam between the box and the body are in place and fine. Thanks in advance. Alex