I am not qualified to talk about replacing parts like these on a spinning reel, indeed if this was to happen to me Id either oil it up and try getting it to turn nice and smoothly, or if it was seized and/or will not freely turn Id be looking to send my reel somewhere for a service (I found an interesting article from Shimano on accessing and oiling up the line roller here)
The length of your flies can vary from the 5 6 inch ones we used when we first started to fish, trying to imitate big baitfish for big peacocks, to the 3 4 flies we have evolved into using imitating tropical fish and smaller baitfish that are much easier to throw and produce just as well on big peacocks
Available in a choice of two colorways, blue or off white
Color: Chartreuse/Frog Size: 6, 1/0
Basically, my pattern was catch big fish, so thats what I did, said Gill