Being the cheap-skate, I would rather spend the extra $$$ on wood,
unless there is a compelling reason why the newer machine is worth it.

I am a tight Irishman myself. My philosophy in being a cheap-skate is to
buy as much quality as I can afford, so I don't have to buy twice. I am not
familiar with the Rigid so I cannot speak to it. However the mid-70's is
the era when Craftsman started moving away from the all-iron machines they
sold previously. I just sold a 50 year old Craftsman 4" jointer and it was
a solid as a fire plug, just not big enough. I also sold my mid-70's
version of the Craftsman table saw and it was no where near the same
quality. It did ok for several years but still, less machine.

If you want to save money in the long run, raise you sights a little -
Delta, Jet, Grizzly to name a few. Frankly, I just put out extra $$$ on a
Powermatic 54A 6" jointer knowing I'll never have to buy another.