If you have never built an alternator before I would suggest starting small(meaning cheap to make) If you have access to neodynium magnets they are the best this list provider carries them.

you would want to start with say a small dual rotor(meaning 2 plates with magnets not just one)
each rotor would have 12 of these magnets alternating north and south poles arond the circle. as far as magnet size i would start with 3/4 x 1/4 inch ones.. they are small and wont give you much power but they will tell you if you made the alternator right by giving proper output for size.

so you have 12 magnets and a circle with 360 degrees..... devide 360 by 12 and you get 30 degrees.... so you need to lay out with a protractor lines radiating from the center of the circle to the outer edge every 30 degrees. so you will have 12 total.

if you use 3/4 inch round magnets then the inner diameter of your coils should be 3/4 of an inch.. most of the time we all make it slightly smaller so we can add an extra 10 or 20 turns in there.

I would make 2 of the rotors i spoke of above... REMEMBER!!!! when placing your magnets you want N S N S N S ect...... put both of your plates together and put an alignment mark on both where the first magnet goes... because on one plate that magnets face pointing out will be a N - and on the other plate the magnet face pointing out has to be S so they attract. once you lay the first magnet the rest will follow as you alternate..... dont worry about actual north and south... just make sure whatever you place down as the first magnet, that the magnet on the opposite rotor is attracted to it.
once all magnets are placed you can hold another magnet in your hand and should feel an attraction on one and a repulsion on the next and so on.... this only works with small   magnets!!!!!! NEVER TRY THAT WITH LARGER ONES OR OUCH!!!

now that you have both rotors assembled, make a test coil with a 3/4 or slightly smaller center and the outer diameter should be no more than 1 1/2 inches(an inch and a half) I got in 150 turns on mine i believe at 24 guage.
make 9 coils...

now 360 degrees devided by 9 is 40 degrees... so you need to place the coils at 40 degree spacing so that the magnets will sweep over the center hole of the coils.

thats all there is too it... its easy by the time you make one generator.
the other thing is to make a mould to hold your coils in fiberglass resin and your stator should be no more than 1/4 inch thick. because thats the thickness of your magnets.

good luck and have fun!!!!!

hope this helps..

How were they damaged?  If the one you didn't tear apart is OK and of the right ratings you might use it for a step-down transformer at your battery shack.  That would let you wind your genny for a high voltage and save on power loss and wiring costs for the wiring runs down the mill and to the shack.  (Then you might avoid winding "N-in-hand" with your wire, too...)

Were they "pole pig"s - power line transformers full of an oily fluid?  If so you may have a hazardous condition.

In the early days those were filled with oil.  Then they switched to PCB - because it insulated better and put out fires if the transformer arced.  PCB was deployed for decades (and also use for fire retardant treatment on wood and such) before they found out it was HORRIBLY carcinogenic and terratogenic.  (That's what accidentally got mixed into the cattle feed in Michigan a couple decades back, when somebody at a chemical plant filled a nutritional supliment order with a similarly named fire retardant by mistake.  Wrecked the beef industry there for years.  Mass graves for whole herds - that had to be dug up again and hauled to toxic waste disposal sites.)

They switched to something else.  But there were a LOT of transformers out there.