Has anyone found a hitch lock (the socket on the A-frame) that fits the 2-5/16 hitch used by Heartland? I have a North Trail 26LRSS, but I'm asuming the same coupler is used on all lines. I had a Reese lock from my old trailer that I liked, but it's "U-bolt" is too narrow for the larger coupler. And the hole in the NT's coupler latch won't accept any padlock.