The Mk 37 was a new director first installed on SIMS class destroyers. When the first SIMS class units were delivered in 1939, they didn't have the directors installed. Those SIMS class units had the Mk 37 directors installed by the USN after being delivered and commissioned. The directors were finally available in mid-1940. SIMS class had priority for installation of fully functional Mk 37 directors, done about the same time they were modified from three quad torpedo tube mounts to two for weight CG correction. The last SIMS class units completed in early 1940 had Mk 37 directors installed as commissioned/delivered including the rangefinders.
The BENSON-GLEAVES class followed the SIMS class in being completed and delivered by about a year, but with an overlap in 1940. For some units, the Mk 37 director was also NOT installed at the time the builder delivered the destroyer to the USN. Particularly true for private yard builders. USN yard builders had the technical expertise to install these "new" fire control systems. For some units, the Mk 37 directors (a different Mod number than the SIMS class directors), were delivered and installed incomplete without the rangefinders (I'm not sure, but suspect other parts of the Mk 37 fire control system may well also, not been installed at that time). I'm not sure if the rangefinders were installed during the USN "fitting-out" process after commissioning or after shakedown.
As a side note; pre-WWII and during WWII, the USN yard built units were commissioned well before the destroyer was "completed". This way the yard could use crewmen to help in fitting out the ship. Private yard built units however, couldn't be delivered and then commissioned, until everything on the contract had been completed or at least noted as incomplete and needed to be accounted for (deducted from payments or arrangements to completion after shakedown).
I have quite a few "as delivered/commisioned" images, but I don't have many photos of these pre-WWII units "post-fitting out". Below is an exception (by accident). These images show USS MAYO as delivered from Bethlehem-Quincy on 18 September 1940, then at Norfolk Naval Operating Base (NOB) dated on 11 December 1940. In the delivery photo, she lacks the rangefinder, but three months afterwards (post fitting-out at BosNY) she has the rangefinder installed and she is ready for her shakedown.
One can build the 1940 BENSON kit "as delivered" or as "completed" after all equipment was installed and the ship was ready for service.
There were six BENSON class destroyers authorized (all six authorized in FY-37) in the first batch of the dual-BENSON-GLEAVES class. USS BENSON (DD-421) and MAYO (DD-422) were built by Bethlehem-Quincy and the remaining four (DD-426 through 428) were built in USN Yards. Basically they were identical, but the USN classified them as two separate sub-classes. So, there maybe be some very minor external differences in appearance when these units were completed. Things like vents and routing of some piping, etc. Otherwise, building this kit as USS LANSDALE (DD-426) should be too difficult and can be straight from the box if the minor differences don't matter to you.
With the King Board Mods, appearances changed in significant ways and some features differed depending on the yard that did those mods..
Just snagged a Dragon 1/350 USS Benson 1940. Would it be possible to make an as-built Lansdale out of the box?