That is an absolute beauty, Jon. I sure hope it checks out as being safe to shoot for you. Doves are great fun with a double m/l. I've only shot them with 16 gauge m/ls, but any gauge would be cool. My first round of skeet I ever shot was with a new to me 16 ga. Powell m/l double. I later killed limits of doves with that gun. Now, my only one is a Manton 16.
Being cylinder bore guns without choke, original m/ls take a bit of a change in tactics for doves, especially for someone like me who likes to shoot LM and IM chokes at doves. No. 8 shot works well at those distances, but 9s do not. Been there, done that. Quail are fun, too. I learned to "squat on the shot", so,that I could look under the smoke and see if a quail fell.
I always use equal volumes of black and shot. Hard to beat that loading technique, IMO. Tried using all kinds of paper shot containers to tighten the pattern, to no avail. I refuse to use plastic shot cups, as some do. If I'm going to shoot a m/l, and use real black, I'm not going to use plastic anything.
Can't wait for further reports on the gun. Hopefully, good times ahead.
SRH