My sympathy as well Partridge!
Gene Autry was also the original singer of Rudolph.
There are free sound editing programs that can be downloaded from the internet such as Audacity and WavePad. Once you have these installed you could spin the disks at a speed slower than 78 rpm sending it to your sound card line in jack. Then use the sound editor to increase the speed back up. This should bring the timing and pitch back to where it should be. Then if you have a cd burner you could re-record it.
                Sandy