I measured the bridge this morning. It is 18" off the pit floor so it's up there. I don't use it unles I am going forward on deck. I usualy step over it onto the engine cover to go below. However it would be simple to make a step.
Here are some choices.
The engine panel and openings for the lazzaretes are 7" off the floor. Your step can only be 6" high in order to be able to see the instruments and open the seats. That would make the next step 12" high. Not great but better.
Materials: You can use teak, mahogany, Trex, your choice.
Step width: You can make it out of two 2x6, 1x4 slats with space in between, between 8" and 12" deep, etc.
Legs: three blocks should do it. One on each end and one in the middle to negate flexing.
I would not make it permanent. Just something you can stow away.
You can make it permanent by using 5200 to glue it to the floor, silicone to make it removable, non skid pads to make stowable.
You can leave it on most of the time but I would stow it if things get hairy. No flying projectiles if you can help it.
P.S. ED is right. That panel is in a vulnerable area. I would make sure it has a plexiglass cover so toes would not get to the gauges, or make the step deep enough that there is plenty of room to step on it.
Hope this helps.