Without the RF top skin installed it’s easier to crimp the BNC plug for the com antenna since the cable can be easily positioned at the correct length.
I found a secondhand Radiall toolset for stripping and crimping the RG400 cable and Amphenol 112514 plug:
After a one-time adjustment the stripper makes 3 perfect cuts:
Crimping of the center conductor pin:
Ferrule ready to be slide back:
Double hex crimp of the ferrule:
With a digital multimeter the cable was tested and found to be okay.