Walter;
Most of the suppliers named will have inexpensive chrome plated brass ferrules, which is what your rods probably have, the only problem is that the new ones are fiberglass rod replacement ferrules that have the wrong shape, the female is belled out to accept the male so the taper of the fiberglass isn't interrupted, glass rods can't be turned to fit like bamboo. If you have top of the line rods that justify the expense then get nickel silver replacements in the same style as the originals from REC or Goldenwithch, they both sell CLassic Sporting Enterprise's Super Step Down ferrules. You can also try www.ricksrods.com for new original stock ferrules, Rick has many oldies in stock and might have some that will fit yours. His price will seem high for what they are, but there are few who have what he has. You can also keep an eye on Ebay, there are always some grab bags of old ferrules for sale there, you might get lucky and find what you want.
john