Series 3 Lightweight Bulkhead Seal

Afternoon!

I'm beginning to conquer the rust on my Landy Bulkhead. One of the main areas of rust is between the upper (vents) and lower bulkhead.

There is a seal, which I can only assume used to be some sort of foam strip between them. I cannot find this seal for sale anywhere on the internet, however I'm sure there will be an alternative or someone may know where to find one.

Can anybody help? Does anyone know where to find such a thing?

Thank you!

That's quite specialist. Try the military part of the forum someone might be able to help.