I would contact Redfield directly. If that did not work I would put a post on the wanted forum on http://www.usrifleteams.com/.
Good Luck
Nat Lambeth
Try contacting Phil Scholl - contact info may be found at http://benchrest.com/archive/index.php/t-42891.html .nat ..
there is a guy in the denver area with parts but i do not have contact info..