Peter,
The pin helped dramatically, but, it did not cure all that ailed that gun. Mr. Orlen put a quick shim on the hook, which finished the fix your pin started. Lever went back to the right side, where it belongs.
Gun resides with a good friend these days, and sees use with 2 1/2 Vintagers 12 gauge loads. If a Tobin has never seen big pressure loads, all seems well. Few fall into that camp, in my humble experience. I, like Tom, also believe the guns end up bent in the frame when abused with hot loads, and have seen way too many of them that are loose.
Best,
Ted