I might give that one a whirl later today DanielCoffey. I find a quad, similar to what the Benhams had for rear mounts, but I have not found a "plain" quad for the forward mounts. I am curious about the structure on top of the torpedo launchers, and will have to attempt to satisfy my curiosity about those... Anyway, close-up detail of the area on the Benham, from a Wikipedia image,
... notice that the forward set faces aft, and the rear set faces forward...
... and here's what I have found in guns.dat thus far, but notice the "pivot" is not "centered":
I wonder if the structure on top of the launchers is a "targeting" location, and one of those controlled both launchers on either side... ??
Anyway, the Class initially had the four torpedo mounts, but in 1943 some re-fits would land the 2 aft mounts, and added more AA and depth charge racks, according to what I am reading at
https://destroyerhistory.org/goldplater/benhamclass/ so we're fine with what they have. If we wanted, we could try a dated load-out, but the main problem is of course finding the "parts"... lol - and what you did for the sil file would be fine.
Edit: In this pic, it looks like the abaft launcher is facing aft... so apparently, they could fully rotate:
It looks like they have a line across to another ship, and might be taking on fuel, while the main deck is "awash"... "nothin' to it!"... notice also that the gun positions are manned...