With simple Windows-based software like Audacity and a multichannel interface, they could record numerous audio channels simultaneously.
If Art did stereo (his voice on one side, guest on the other), that would take up more channels, but be invaluable.
I don't know if there's a practical track limit in Audacity, but a decent computer could handle 24 channels of audio to capture.
Spend $100 on some multi track software and you could effectively record 48 channels.
In theory 4-8 weeks of shows in 5 hours if they have enough decent VHS machines.
After digitized, editing is a snap. Hard break times being the easiest to find. Looking at wave patterns will find other breaks, even if a live read because his cadence will change.