I did the same thing....called my local Jayco dealer and gave them my VIN. Apparently, the company that made the locks and the keys went out of business. Thankfully, I had already found a solution and I have pasted the Amazon address below. It's a hose bib key and despite being a 38 year old woman who knows a lot about horses, English Lit, and teenagers, I know nothing about construction and home improvement stores! When I went to my local home improvement store and asked for a hose bib key, they looked at me like I was nuts. NO ONE had ever heard of one! So, I did my research and my gut told me it would work. Voila. It does. So we ordered three of them.
Hope this helps for anyone else with this problem!
In case the link ever stops working, ours is called the Cobra Products PST154 4/Four way Sillcock Key. I don't remember which of these four fits (4-way key fits 1/4", 9/32", 5/16" and 1/32" stems), but one of them does and works great. I did try socket wrenches, another tool thingy from Lowes (some type of heat vent key thingy from the plumbing section), and Hex Key sockets....but the key above is great.
Hope this helps others!