A quick search seems to indicate "PB" = "Praktica Bayonet". If you can't find the adapter you want you might want to talk to a machinist company, such as S.K. Grimes to see if they could either make you an adapter, or change the mount on the lens directly.
I looked into the Jenazooms a couple of years ago - interesting lenses, very nice zooms from the samples pics I've seen online. Most of the lenses were designed by CZJ, but manufactured by a 3rd party (many say it was Cosina, which makes sense) in the late 80's and early-to-mid 90's. Unfortunately they are not terribly common, particularly in K-mount which is what I'm primarily interested in. Other mounts pop up from time to time - I see a couple of M42-mount versions on eBay at the moment, but due to moderate cult status among zooms they all tend to go for more than I'm willing to spend.