My favorite edition of "Six Studies in English Folk-Song" is the adaptation done by Paul Droste, formerly band director of The Ohio State University Marching Band (aka Best Damn Band in the Land). He is also former director of the Brass Band of Columbus and served two terms as chairman of NABBA. He is also a euphonium player and recordings of his performance of the work are available.
In my version, published by Galaxy Music Corporation in 1986, the first movement is in concert F and starts on the mid-staff D. This is down one full step from the original Vaughan-Williams work for cello. That one full step helps out a lot in several of the movements. It includes piano accompaniment in the transposed keys as well. Droste's recording is of this version. I think I downloaded it from Apple some time ago.
See if you can find this online. If not, PM me and I might be able to help.
Doug
Adams E3 0.60 Sterling bell - Prototype top sprung valves
Concord Band
Winchendon Winds
Townsend Military Band