No doubt they will weigh this up, but they can argue that things are different now. Earnings are much higher now than they were then etc etc.
I don't think shareholders are going to revolt either. If they do a buyback and they helps lift the SP further then the capital gains is all that people are going to care about.
If they just do a tax free a capital distribtion then the amount they can return that way is capped at the net proceeds they have from the asset sale (so somewhere between $50M-$55M). They cannot distribute any of the cash that has come from operations in that tax free manner.
If they do an on market buyback, they could use much more money if they wanted to.
Another option could be a 'tender offer' type arrangement where they offer to buy x amount of shares at the closing SP + some % premium. But that might not generate the interest they would like, and is my least preferred approach.