Jackpot.
I found a company still selling the 509's. They have in stock, both the red and the amber. Here's the link:
http://www.slclighting.com/user/prod...il.php?pid=285
I could not get the online order process to work, but I called the number provided and ordered that way.
A user on motorhome magazine's forum listed a different part number he had used and I was able to find them that way. The original company is now owned by a new company and this is a distributor for them.
Down the road.
Larry P.