I'm guessing your assumption is likely right as that one of only two places they could go. The other would be between the action and the stock, but that wouldn't make much sense and they would likely end up curved to match the curvature of the action if in that location.
Only other possible location would just be for the rear one which would be between the magazine housing and the trigger guard.
Just have to do aa little trial and error to see what looks/fits right.
Bookmarks