The trigger guard spur...I use a two hand hold when I'm serious which is most of the time. I'm left handed, so I grip the butt of the pistol in my left mitt so that the pistol is directly in line with the bone of my forearm. Then my right hand goes around the fingers of my left, and the index finger of my right hand grips the spur. My right thumb presses down behind my thumb on the left hand. I'll get Daryl to take a picture...worth a 1000 words, eh? So yes, the spur is useful.
I made the parts for my swivel, and it is a very useful accessory to the pistol. The brass end of the rammer makes a comfortable addition to the 1/4" steel rod for pushing the ball down the bore. When you pull out the rod, the swivel centres the rod perfectly in the bore. The brass knob is exactly the right size to use as a jag. So I pull the rod out all the way, reverse it, and use it to clean the pistol, when I don't remove the barrel. But, the pistol has a hooked breech, so I always remove it to wash it thoroughly after a day at the range. The swivel is not fragile. I think it's original purpose was to prevent the rod's loss, especially loading on a galloping horse.