In this case, it's the "7.3 Excursion", as these hoses were only used on Excursions, and not 7.3s in general. Demand fell off, and the part was discontinued. (I have no idea if the 7.3 and the gasser Ex use the same hoses, but either way they're discontinued).I'm just shocked that with how popular the 7.3s still are, there are parts not made at all anymore.
Hopefully, the links above can provide what you need.
I looked at the pics in the links posted above. The long one could probably be replaced with bulk hose. The shorter one could possibly be made up with two generic 90deg bend hoses with a coupling. There are ways to make something work if you can't find the OEM part. Sound like you have it in a shop that will figure it out.