Great stuff, Jim - thanks for sharing those. It looks like an evolution of your approach on the Hookjaw Strip reprint, and it works very well here. Glad to see Rebellion/you went the extra mile on this, though I suspect it just wouldn't be viable on some lower-profile reprints with machine lettering - Charley's War strikes me as a bit of a perennial seller, and it has a particularly high profile in this particular year, so the extra time and expense involved in re-lettering would be justifiable.
re: colours. I've done a fair bit of experimenting with restoring scanned colour pages. On one project, I took the colour pages, stripped down to the linework and recoloured from scratch with colours that matched the original printed comic. On others, I've worked on restoring the colours already there. Both approaches have their issues, IMO:
-- Recolouring scanned art. You have to be fortunate enough with this to have a couple of things - a good-quality source with a clean original print, and an artist with reasonably strong linework. With that, I would scan at high-resolution, convert to CMYK and pull out the K channel to give me what is essentially a page of inks. Cleaning those up will give a reasonably good base for recolouring, which would follow the typical computer colouring process (whichever one you particularly use). Unfortunately, what you normally have is a poor-quality source - misaligned printing plates causing artifacts, bleed-through etc. - and when you pull out the K channel you discover half of the linework is actually on C, or the linework is patchy in general. Then you have a lot of reconstruction to do, which is painstaking and frustrating, before you can even think about recolouring. On top of that, I found that even the closest approximation didn't look quite right for reasons which I'll get to in a minute.
-- The alternative is to scan and clean up the page as is, with the existing colours. Again, if you get a fantastic source - flat, clean, decent original print - this should be relatively straightforward. However, most extant available comic copies are damaged, worn, aged or have original printing artifacts. With this approach, the most common issue I find is patchy colour or misaligned printing. With the first approach, you can do some correction for misalignment (or you can dodge the misalignment issue entirely if you're lucky) but with this, it's far harder to deal with. Patchy colours can be corrected by use of various tools - cloning/healing brushes in PS don't work brilliantly for me, as they tend to "muddy" the process dots in a way I find quite noticeable on the finished piece, so I often resort to simply cutting and pasting patches of colour and carefully blending around the edges to cover up things like staple holes, paper damage, poor ink distribution etc. Again, quite time-consuming.
At the end of the above, you can get a clean page with relatively accurate colour reproduction, but I always find the colours end up looking slightly off. Often, they end up a little over-bright/over-saturated as you compensate for the washing-out effect of clean-up (and I've seen some that just look plain washed-out compared to the original).
I've gone back and forth on this quite a bit, but I've started to come down on the side of people who have restored US comics of an earlier vintage: the colours were picked by artists who knew the process and were anticipating that their work was going to be printed on newsprint, and if you're wanting to get as close as possible to the "genuine" look you have to consider either printing on a suitable stock or you have to consider something like using a filtering layer on the restored art (which seems crazy and counter-intuitive!) I'm unsure of which option would be best, though I've seen some good examples of both, and to be honest, I'm unsure of whether it would even be received well by the intended audience - would they appreciate the extra lengths taken, or would they turn their noses up at this kind of restoration? I think most modern readers are conditioned to see clean, white (often glossy) stock as "correct" and uncoated, cream paper (or a flat, cream newsprint filter) would look wrong to them.