Seydel also makes a Low Low F !
I was reminded at the Buckeye, that these Seydel Low harps should not be stored laying flat, due to the added weight (solder) on these low reeds.
So store them standing up (holes on top) or vertically (like in the Hetrick harmonica case).
Ken H in OH
I wouldn't worry about that. The weight on the reeds is surely not stress enough to go over the elastic zone of the metal... No need for special storage methods. But I do prefer cases where the harmonicas are placed on the short size. Saves space.
Cheers, Fernando