I do not know about the hose, but I think the clamps are readily available. Actually, you buy a length of strapping material and the cotter key clamp roller. You can check the usual vendors. I inquired some time ago, and Millers had them, there are two sizes, so you can double check with them.
The "Total Restore" does an excellent job of showing you how to install these.
Pete Lesler also sells/sold these. He also has the Norma style clamps available. He had a bunch at Blacklick last year.
Jonny B
1967 250SL Auto