I have 10 super 8 sound films in cartridges. Seven are 600' and three are 400'. It is possible to break open the plastic cartridges and hand wind them onto reels. The titles are about skiing.
Free. These films have been claimed!
Below are just a few ideas I got from a guy on a bicycle at a pawn shop.
You can also use the plastic cartridge platters to unload feature films like Gone With The Wind from damaged reels onto apple cores. Just super glue a small metal handle form the magneto off your uncle Bob's 1950 Studebaker(Bullet) onto the plastic platter. This unload can be performed easily by standing on one hand while resting your legs on the island counter of any convenient kitchen. You might want to video this for future reference just in case no one believes it can be done. Oh, be sure and shave your head and wear a tie dye shirt with a vague image of Che Guevara. The more you verbally bullshit your way through the video, the better it will work.