SECOND ADDENDUM
In the OP, I mentioned how I regretted not being able to take a clear shot of the cases in profile. I'd like to rectify that now.
Lightning strikes twice, and I saw Mr. 6263 at my watchsmith's again. I had my camera but not my Daytonas so a direct comparison under similar lightning isn't possible. I did try to match the angles when I got home, though.
Gen at bottom:
It's worth noting the slightly higher crown and pusher positions on the gen. The thinner mid-section is also easier to detect in the low-angle shots.
The lighting of the rep shots makes the bezel lip look thinner than it really is. If you look at pictures in the OP, the DW bezel is a near-exact match to the gen in profile. Compare it with the thin-rimmed bezel on dmacnz's cartel 6263.
Gen on right:
As previously mentioned, the lug tips on the gen are wider. Surprisingly, the DW is too thick on the crown side, yet too thin on the right.
Finally, if you're wondering why the rep 6263 has a straight-brushed finish... It was a poorly researched mod! Of course, a gen owner may have had a watchsmith brush the caseback for whatever reason, but it's something that's generally seen more on 6262s and 6264s. As always, there are no hard rules when it comes to vintage Rolex.