I looked up the HS-50 and Tower Hobbies show them to be discontinued. When I compare the specs to the Caswell servo, they are almost identical..at least dimension wise.
L = .82", W = .44", H = .87" Torque = .6kg/cm
interestingly it also states "For 4-cell (4.8V) use only."
Caswell Micro Servo BT50
Size: .45" x .8" x .85" (doesn't identify the dimensions)
Torque: 1.6kg/cm @ 4.8V (seems like the torque is VERY high compared to the HS-50..) Cheap Chinese no-name brand has 2.66 times the torque of the Hitec unit?? I wonder if that is really true.. Anyway, it would appear the Caswell servos will fit inside a 1.5" WTC in the same way your HS-50s do.
When I actually have something to show, I will put it on here. I am still waiting for the hull to arrive... The hull is in the process of being laid down at Deutsche Werft AG. We can never seem to get these "Wunderwaffen" boats assembled in a timely manner! When the hull finally does arrive the internal components will need to be installed in the most adverse of conditions.. Hopefully the boat will sail before the war ends..
I crack myself up sometimes.. Anyway, just doing preliminary planning for my own little WuWa project to gradually work on over the summer.