To re-visit a concept I had a while back, I think it would be pretty do-able to digitally tweak Sebastian Shaw at the very end of ROTJ to better represent Anakin's "canon" age in the franchise.

Basically, the changes are as follows:

1) added shading on his neck to make it look less flabby

2) Re-colored hair to look like fading blonde rather than gray

3) added a layer of skintone in some spots to hide some of the wrinkles (mainly aroung the chin/mouth)

4) Used a mesh to push in the ears and sides of the cheeks to make them look younger (since a we age our ears get bigger, and sometimes our cheeks and necks puff out)

Here's a comparison:

As you can see, the original is pretty clearly an elderly man, whereas the retouched one looks more like a middle-aged man, which is more in line with what Anakin is supposed to be at this point.

And, for old time's sake, here's a comparison of the retouched version of Shaw with that very out of place, vacant-eyed Hayden Christensen footage from the 2006 DVD.