John, thanks for the further clarification - I think I understand it now.
I just ordered a new Hohner 364 (12 hole) in Low C. I can't wait!
Although I'd LOVE to score a vintage Echo Vamper!!! As I understand it, Hohner marketed the 364 over in the UK identical to the "Echo Vamper" except for the cover plates. (not to be confused with the Super Echo Vamper - not the same thing)
Some say to keep an eye out on the UK ebay site as they pop up every once in a while.
And check this out. It is an entry on Dave Barrett's website chugging competition. This particular chug was the second place winner and was done on a Echo Vamper in Low E. It's awesome IMO.http://www.bluesharmonica.com/strollin_down_tracks
(You need to click the play button on the little 'Audio' icon under the title "Strollin Down The Tracks)
Low F is off course fun
Bye Bye Bird is best played on a Low C harmonica, that's why it sounds lower as your Low F.
Low D is lower than Low F (G is the lowest normal harmonica) going more down you will find
for example Low F, Low D, Low C. The lowest I know is a Seydell Low Low F, it takes special skills to make that one sing.
have Fun, John