I used to deal with Rocko at CT Mustang II,(Located in Stratford, Connecticut) but I havent called them in ages.
They used to regularly have a couple Kings and some other IIs for sale, as well as any part you could imagine, both NOS and repro. In fact, I got all my repro weatherstripping from them. But as I said, I havent called them in years, so I'm not even sure they're still in business.
CT Mustang II - 203-377-4795