You seem to have made sufficient diagnosis to determine the film cartridges are likely to be faulty. Maybe 15 years in the freezer has caused degradation of the plastic gear, else, possibly more likely, the film itself has taken on so much of a "set" that the very act of unwinding it is too much strain on the mechanism, or even that the film has stuck to the paper backing … I've known very old 120-roll film do this.
With nothing else to lose, I'd try simply leaving a film cartridge in a warm (not hot) place for a day or two to see if it "loosens up". Disassembly of one of the failed cartridges may also reveal the problem.
I remember having some 100ft cans of very out-of-date b&w 35mm film stock with a very tight "set" from long storage, an absolute pain to reload into a 35mm cartridge, but the "soft yet grainy" results were unlike anything else