You know, a spanner wrench might work for what you want. What is the diameter of the forend nut on your .410? I'm guessing it is around 1" to 1 1/2". One of these might work. https://www.mcmaster.com/spanner-wre...on-the-face-6/
Heck, go out and see if you have one for an angle grinder. They often use this type of spanner for their nut.