Are you sure it’s a Sleep Number branded air bladder mattress? For many years Winnebago installed Ideal Rest brand air mattresses in their motorhomes. It’s possible that older RVs did use Sleep Number brand product, but certainly the past decade or more it was a knockoff product from InnoMax in Colorado. Certainly owners called these “sleep number” even though they were not.
Here’s an old post from here but there are many others all over the web.
https://www.winnieowners.com/forums/...ma-357070.html
As to the wired controllers, the cable between the hand held controllers and the system was a standard Ethernet cable on my Ideal Rest. This would explain how the got the wire into the cabinet with a hole smaller than the controller itself.
Here’s a link to InnoMax for Ideal Rest parts:
https://innomax.com/product-category...acement-parts/
Mind you, I’m not saying that yours is definitely an Ideal Rest, it may be a Sleep Number or other brand but I wanted to provide some information just in case.