Jim - Excellent rifle and best quality, I love the rose and scroll engraving

You are probably right that the prince wanted that particular combination and may have had it to order, against buying a standard 12 bore
16/14 bore is certainly unusual, even a one off?

The cases may, as you say have been made thicker for the higher pressure

The flat hammers are less common on later rifles, except some of top quality - Ideal barrel length

I hope you can get some cases/heads an tell us how it shoots!

With a weight of 13lbs 10 oz recoil should not be too bad, unless you give it the full 9 drams!
(my own H&H 8 bore ball gun at 16lbs lets me know with 10 drams)

Many thanks for posting

Tony