A logical assumption would be that the two reels had the same size of reel foot or if not the smaller reel would have a smaller foot. When I made the reel seat I used the small Hardy as a "test" and had a great fit with the sliding band. I wondered if the bigger reel would fit on the small seat even though it looked "silly" big to me. Well guess what? The big reel foot was too small and the ring had a sloppy fit. What is the lesson in all of this?
Even though modern reel makers claim to use the AFTMA standard dimensions for reel feet they don't. As bamboo enthusiasts a lot of us have older reels by Hardy, Bogdan, Pfleuger, Ocean City, Meek and the like and every single reel has a different size foot. It is very easy to make a great rod and then the reel seat you have chosen will not fit the reel. This happens more than you think. When I make a rod for a customer I insist on them giving me the reel that they want to use and I fit the reel to that rod. Other reels may work too but at least I know their number one choice will have a great fit. Tell your customer that reels are unique and that it is possible that other reels may not fit. The Payne style screw lock seat offers a much larger range of fit and it is mostly the sliding band reel seats that are a problem. People would devise elaborate shims or tom pieces of cigarette packs to take up the slop and this was an accepted practice. Make sure that you fit the reel to the seat before you glue up anything, it is an easy problem to fix. Find a reel that you have that fits a lot of rods and use it as your test reel, it will save you both heartache and embarrassment if you deliver a rod to a customer that will not fit his or hers favorite reel.