Is this spring being reproduced?
I have seen vendors at swapmeets with tables full of different door hardware springs. I personally don't know who would have that exact spring. Did you try to contact Dennis Carpenter? Even if they don't have it they might be able to give you some leads.
I think you should check this uPay auction:
http://cgi.ebay.com/ebaymotors/Door-...ayphotohosting
It might not be exact but it sure looks close.
You can try this place:
http://www.vapinc.com/brass/main.html








