I hate to sound like a wise guy, but have you tried Mossberg? Any time I need a part they have been very helpful. Their prices are not crazy high like Winchester was and their service is pretty fast. They get kind of iffy about triggers and sears due to liability issues, but I am sure a trigger guard will be no problem.
Thanks for the advice guys!
I was really hoping to find one locally, cheap w/o shipping, etc.
I have a Mossy 500 with a broken trigger assembly that I'd like to fix and sell.