On your bands, I would suggest you pin them on with at least 3 pins. With changes in temperature the cast resin and the brass will expand and contract at different rates. They will eventually come loose. I would also rough up the inside of the band and the area where it covers and use B Weld to epoxy it in place.
You can buy gas welding rods in various sizes that made of brass, Cut short pins, I drill my hole for the pins through the band and into the barrel, but not onto the inside of the barrel. Mix up some epoxy, stick a little epoxy in the drilled hole, then drive the pin home with a ball peen hammer, this will fill up the drill hole. After all holes are pinned, I remount on the lathe cut off the tops of the pins flush with the bands. Sand through the grits to 600 and buff them using rouge and white diamond wheels.
You can also cut rings in the bands with the corner of a skew, leaving a wide band in the middle and 2 smaller bands on the outer edges. If you have a Dremel with a 1/8 ball you can "stipple" the center of the band and then polish it. Makes it look like a high dollar custom band. If you do this, make yourself a mandrel and do the fancy work before you mount on the barrel, you will screw up some of them, Better to do it before you pin it rather than after you have done all of that work.