A long time ago, on one of my builds I used Ol' 55, in Eastern PA. Couldn't find anyone in central/north Jersey.
I think Jerry still does them, here is a link to his profile page; http://www.jalopyjournal.com/forum/members/homemadehardtop57.43072/
There was a New Jersey louver guy, think the name of the shop was Soprano's, or "Botta-Bing", something like that. He had some 'family troubles', think he does license plates now...