Dave,
I just wanted to clear up on how you would remove said dent in the 1st valve loop. A technician usually as a huge set of threaded dent balls in increasing sizes that can be attached to flexible or fixed rods. In this case you would use a flexible rod to enter the first valve loop and get to the dent behind the curve. Just pulling dent balls through in increasing sizes should do the trick.
Magnetic dent tools work great on larger dents in the larger areas of a large brass instrument like the bell, bottom bow and if you’re lucky the top bow. They need a large, heavy magnetic dent ball to be able to roll the dent out. In this case you would only be able to fit a smaller dent ball and that wouldn’t do much as there’s simply just not enough mass.
Other than the dent this looks like a great deal.
Music educator - Brass Instruments Enthusiast - Euphonium Player
2019 Besson Sovereign 967T-2 - Alliance DC3