There are a couple of variants of the shake out bag for the XXX, I've seen at least 3, including the one mentioned above advertising the LX. There are also a few aftermarket variants around. Good question about the filters, I've been using a homemade filter for my 2 30's made from a layer of carbon cut to fit A/C filters sandwiched between layers of electrostatic filter cloth. They do a very good job but it's a bit fiddly to get all 3 layers in place sometimes - especially if I'm not being patient. I keep my eyes open for the originals on the bay as well. Hoses also changed pre-war vs. post war. I have a creamy beige one from 1947 and a greeny-gray one from 1939 - or maybe the other way around I'll have to go look. I pull those out the least. I use a replacement hose most of the time because I don't want to damage the originals.

Kevin,

I don't notice much difference between my homemade filters and the originals... but with no filter there is a slight increase in airflow.