Hi I have an old but reasonable condition SAS/Para bergen, the same one with the steel frame that was famously used in the Falklands.
Sadly due to old age and over use, some of the Butyl-laminate waterproof coating is strating to falling off, in a couple of areas it's all gone.
I don't use the bag often, but I find it really comfortable for day trips (though it is heavy). I don't want to ruin the bags looks or remaining proofing.
I have a feeling the answer may be silicon paste.
Sadly due to old age and over use, some of the Butyl-laminate waterproof coating is strating to falling off, in a couple of areas it's all gone.
I don't use the bag often, but I find it really comfortable for day trips (though it is heavy). I don't want to ruin the bags looks or remaining proofing.
I have a feeling the answer may be silicon paste.