What a mess.
I didn't have the Floating Drydck plans when I widened the hull the appropriate 4' each side and faired it into the bow and stern using photos of the Yorktown from 1993, assuming that the Revell hull was accurate except for the widening, so with the additions being no more than .08" how wrong could I be? But the further I got into looking at photos I realized that my Essex was looking kinda stout around the forward midsection, so today I cut out the hull sections (focusing on 26, 41, 51 and 62) and attached them to a jig set alongside the model base to see how accurate the forward hull really is.
It's not good. As shown to the left, fames 26 and 41 - especially 26 - which are forward of the added hull width - are hopelessly too wide. By (aggressively) sanding with the Dremel I was able to get frames 62 and 51 (shown to the left below) almost dead on, but couldn't get much more than a quarter inch in the forward sections without sanding through the original kit hull.
The problem is the the original Revell hull is too broad through the waterline. The Essex class had a hull shape not unlike the Yorktown that has been analogized to a Coke bottle shape - very narrow as it goes forward. This was missed most famously by Trumpeter's 1/350 Hornet (CV-8), but this is a similar error. The hull shape is just a generic barrel, narrowed at the bow and rounded at the stern. In fairness, it's much more accurate than the other ships Revell was putting out in 1956 - the flat-bottomed Missouri and Midways come to mind - but it isn't accurate for the Essex, either as-built or modernized.
I didn't fully realize this with respect to the SCB-27A ships until I saw a video about the 1/350 Intrepid kit (hull shown at right) and realized that the Revell hull shape was too far off to let alone, even this late in the build.
But what I discovered was that the error was much more than the thickness of the hull itself. So while I could theoretically sand through the hull and reframe the entire thing from the inside, that was more work than this resurrection build really needed at this stage. So I sanded as much as I could to try to get a concave hull cross-section, and puttied over it.
Now I already knew the bow was not fine enough and had hollowed out the extreme bow to try to get a better shape for the cutwater, but the problem just got worse from there, it turned out - the model is just too broad back to frame 51 or so.
I would recommend that anyone seeking to accurize the Revell kit use the FDD cross-sections and rebuild the forward hull from the forecastle deck down - essentially start the rebuild by accurizing the entire hull, rather than just slapping on a double layer of .04" sheet to represented the widened hull as I did. That gets you most of the way, but if you want the best result - rebuild the forward hull.