Well gents, I think I've come up with a solution to this rangefinder \ fire control director issue!
I decided to do a 3d model of the Mk 19 fire control director as found on the USS Northampton (posted earlier here), and associated range finders for the spotting tops of the USS Lexington and Saratoga in the 1930s.
The rangefinder is based on a few ship-side photos and the plan-drawing found in Kagero USS Lexington 3d plans. (A problematic source, but photographic evidence supports that the range finder is at least correct).
The Fire control director and round platform is based on the one good photo from the USS Northampton that someone graciously posted here; and several images of the better documented but later enclosed Mk19 director with it's housing removed.
I've placed the forward directors on a rectangular platform that fits inside the rectangular spotting top platform. I don't have any direct evidence of this existing, but there are numerous photos showing the head and shoulders of sailors standing above the wind-break, as well as the very top of the director (what appears to be a sighting mirror?). Given the overall height of the windbreak and known height of the director, there would almost certainly have to be a platform inside the spotting top to allow for this much of the sailor to be seen over the windbreak. A few of the side views posted earlier in this thread also appear to show some sort of platform inside the center of the forward spotting top.
I designed the aft directors inside their tubs, exactly as shown on the Northampton and seemingly confirmed in at least one photo of the Lexington or Saratoga from the 1930s. The only difference is that the tubs are enclosed with canvas, as is shown clearly on several period photos of CV2 and CV3.
I can't swear to these being 100% correct, and as I find more source documents, I will update these items as necessary.
I've also included the sub-caliber guns that go in between the barrels for the four 8" turrets. A little random, but I needed to replace one on my Saratoga set, and no current detail set includes these as far as I'm aware.
I have listed this in my Shapeways shop if anyone else is interested in using this solution. The photos of my WIP Saratoga are using the excellent Model Monkey 1936 superstructure. I have various photos of the renders, actual printed parts and source photos used here:
https://www.shapeways.com/product/6H8VJ ... ge-finders Best,
Trystan