Zephyr I would either use the gun mounts for the AMerican 76mm used on the HMS Eagle, the british 3in/70 or the AMerican 3in/50RF Marks 27/33/34 and if possibly with modified sponsons the 4.5in. model described with Rowdy, the 3in/70RF Mark 37 or 5in/54 Mark 16 these latter three may be too large though
glad to see your back to drawing