I believe that the H146 masts were made by the Dwyer Aluminum Mast Compay. Here are their contact details:
2 Commerce Dr.,
N. Branford,
CT 06471, USA
Phone: (203) 484-0419
Fax: (203) 484-2014
E-Mail: sail@dwyermast.com
Of course you should also check out Hunter Customer Service:
Hunter Marine Corporation
Route 441, Post Office Box 1030
Alachua, Florida USA 32616
http://www.huntermarine.com/ContactUS2011/ContactIndex2.cfm