Constant to Momentary, On and Off

Hi all, I am new to the forum but have been looking around a while -- this seems to be the best place to find information and advice with respect to 12v DC circuits.

I am a sailboat owner and I am trying to figure out a control circuit to action a relay that switches the power supply to an SSB radio on and off. I currently have in mind using a Cole Hersee / Littelfuse 24200 latching relay. Details here:
* https://www.littelfuse.com/products/dc-solenoids-and-relays/bi-stable-latching-relays/latching-solenoid/24200.aspx
* https://www.allbatterysalesandservice.com/browse.cfm/4,2914.html

I would like to action the relay in two ways, one via my standard electric panel where I have spare circuit breakers. As a result, I would like to design a circuit that takes constant power in and outputs a momentary discharge. I.e., a combination of these two circuits:
* https://www.the12volt.com/relays/relaydiagram20.html
* https://www.the12volt.com/relays/relaydiagram71.html

I have drafted the below, but I am not sure it will achieve what I want. Secondly, in the diagram below, in the normal scenario where B is opened while A is still closed, then the circuit generates a momentary positive output at C. But in the scenario where A is open while B is still close (my electrical panel loses power) then there should not be anyoutput at C at all. Is this achieveable?

Thanks in advance