According to the REV parts website, the "legacy part" corresponding to that part number is a "MODULE, CONTROL WIPERS WASHER HEADLIGHTS HI/LO TURN AND H" and they list it as "obsolete" with "no replacement per supplier."
REV Legacy part number : 16626855
I'd contact them to see what they recommend or if they can direct you to the original supplier. As you know, they are the "new Monaco" but still deal with and carry some old Monaco parts.
I looked further at the ebay link that h20ski
posted and it appears to have expired several years ago and that seller has "zero" listed as "available."