The Columbia 26 MK2's rig works. Not a lot of ways you could actually improve it and if I came across one with a rig in good shape I'd leave it just like it is.
That said, any boat this old is, more than likely, ready for a new rig... The rule of thumb is standing rigging and related stress points (toggles, chainplates, tangs, and suchlike) should get replaced every 7-10 years or so, as well as some serious attention paid to the mast while you're doing it. What can I say but metal fatigues. Sadly, I'm pretty sure that about half of the boats in this age bracket have their original rigs or at least parts of their original rigs in critical places... Needless to say, this can be problematic.
Sails can also be a problematic point as the other day I came across an ad for a C26 which boasted that the boat came with the original sails in "like new" condition.While old (seldom used) sails may look great the thread they were using in 1969 probably has quietly expired what strength it had back when Jimmy Carter was President.
Replacing big chunks of the standing rigging and buying new sails could cost a whole lot more than the boat is ever going to be worth... So it's really something you should be looking at closely.
Later we'll talk about how to redo a stock rig in a frugal fashion or, even better, how to replace it entirely with an even better more VolksCruiserish rig for less.
Next up we'll talk about engines and rudders...