Take a look at this old thread:
https://www.keystoneforums.com/forum...t=46500&page=2 Specifically post #14. There's a link to the actual circuit board that is very likely your problem....
I really don't think you'll find the "entire switch panel" that was installed in your trailer (the panel with the slide switches, light switches and tank status indicator LED's).... Those "everything on one glass panel" are most often a "one year use before the factory changes to a different configuration".... After 10 years, chances of finding the entire panel laying on a parts shelf are pretty slim.....
So, "go for the individual parts" since they were used in thousands of trailers from every manufacturer, from Forest River to Jayco to Keystone.....
If what you're looking for is like this photo, chances are it will be impossible to find 10 years after being installed. So, look for the "electronic circuit board behind the panel"...