I liked the way you did your wiring, nice job!
The breaker box is a basic Square D 2 circuit slots. Home depot Square D Model # HOM24L70SCP Internet # 100202333 Store SKU # 565539
The 20 AMP breaker is separate and located right next to the breaker box area.
Also, check this dog bone RV 50A Male to (2) 30A Female Lighted "Y" Adapter by ECS electric cordsets. I called them, very knowledgeable and helpful.
RV 50A Male to (2) 30A Female Lighted "Y" Adapter
This adapter allows you to be at an older RV park that only has a 50 AMP outlet on the pedestal and no other outlets available. (Had several like that on my trip out west last year).
It splits the 50 AMP service so we can individually power the coach and the 2nd AC from one 50 AMP outlet. Very cool.
Let us know how this project continues.