I am sure you can use them but you will need to do some experimenting so don't expect an easy answer. I don't think you have enough magnet to do a 10ft machine, but without knowing what your magnets are it is impossible even to make a guess.
65 is a no go so say 64, that makes sense to try 16 poles with 2 magnets stacked radially per pole. You will probably need to increase disc diameter so that the gaps are about equal to magnet diameter. Use 12 coils and you will need to guess a prop diameter so that you can choose a cut in speed. Make a test coil about 1" thick with hole about 3/4 wide and 2" long with sufficient wire to touch its neighbours ( draw out 12 coils to get the size).
When you have found your turns for 48v cut in you can choose a wire size to fill the winding area and then calculate the resistance. From that you will be able to see if it will take a 10ft prop. When you find that it won't ( very likely) you try for an 8ft prop and see if that works. You should find all the details about test coils and calculating output from resistance here somewhere. it will be a long slog if you are way off first time.
If the magnets are neo then try for 8ft as a first attempt. If Samarium Cobalt then try 7ft. If they turn out to be some bonded rare earth material you may be down to 5ft.
In some ways it may be better to try using 8 pole on something like 8" discs with 6 coils and doing a small test alternator. That way you could still establish the flux level you have with much less effort and outlay. If from the little machine with 16 magnets the flux level looks promising enough to proceed to a big one with all the magnets then you have a lot of useful data. If you stick the magnets with superglue you should be able to remove them if you decide to go for a bigger version.
Just one final point, check that the poles are at the ends of the cylinder, if they are from a separator that seems likely but don't assume anything.
Flux
