I used CA on my T-55 tracks and most of them are still flexible, however a few of the links are solid,. Is there any way to 'soften' CA so I can fit the tracks?

I suppose you could apply a very small amount of acetone along each joint with a small brush.
I would test it first. Since acetone is used to release CA items stuck together, a very small amount applied to a joint should do the trick. Just use it sparingly.
Hope this helps.
Good luck!