Sombody was looking for side louvers, but I can't find the thread now, the yard I saw them in was Tosey's in Wrentham , Mass. I found their phone# without the area code, it should be 508-617-or 781 in that order, the # is 384-8777. Give them a try. the town has been trying to put them out of buisiness, so I'm not sure if you'll get threw, but give them a try, they may only answer a couple of days a week. I know they had a couple of sets last summer when I was up there.
Good Luck. If you need me to drive up there, I'm heading up past there after work on tuesday. I can see if I can find anything out after hours. Let me know.