Exceptional find - congratulations. Definitely pattern 10b, and dates to late 20s.
That's also a low-use reel to have such good lead finish remaining, and red agate puts it over the top for demand-side.
Here are examples at each extreme:
You can see this Manwaring of Paris is missing very little original lampblack.
Some of these reels came with a 2-3/8" foot, which fit anything, and improves their value in current market.
The longer 2-5/8" foot is tougher to fit, though plenty of period cane sliding bands, and pocket/screw seats on glass rods from the 50s and 60s often work.
One in particular, this pattern 16a long foot on H-I period Harnell 1652.
btw, here you can see the more domed appearance of the pattern 16a winding plate.
The later reels are mostly Japanned enamel finish.
The smallest pattern 16a was 3-1/8"