I have both a couple of older 700s and a couple of newer(w/j-lock) and I havn't been able to tell the difference. I do know that there are replacements that dont have to have the j-lock but their not cheap. About the brake, can't you remove it? I have seen them that come off and have a small sleve that protects the threads. But if youonly bought it for the action what were you going to built onit? Good luck. Jovan