Thanks to all for the recommendations. I had already tried each one before writing here and without success. But today I made a trip to some suppliers in my region. Camping World took numbers and pics and will try to find one. The Jayco Rep started a search after visually inspecting my light and will get back next week. A trucking supply co. recommended by Camping World couldn't find one but recommended two other places - Freightliner and another RV place with big inventory that I can contact next week. So the search continues, and I will let everyone know if I become successful and pass on the info for any other Sprinter owner who may need a clearance light.
Thanks again and ...
for the poster who made an issue of the fact that I posted on two forums with this question, rest assured I will from now on limit posts to one forum only.