Is that "One Kind Favour, I'll ask of you - See that my grave is kept clean". ?
It is indeed a great song. I played it as a teenager.
I don't think I ever heard the Hammand version but Peter
Paul & Mary did a cover of it in the early to mid sixties which is published in one of their songbooks. And yes the chords are not what you might expect if you are a typical C G D7 kind of guitarist (like me). No the tuning they give is not non-standard - but that's not to say that Hammond did not use a non standard tuning - or that they did not either and merely reported the chords in standard tuning in their book. I have found their arrangement difficult to play as written so they may well have retuned their strings for this number.
If you don't have access to the PPM sheet music I may be able to help. It might take me several days to find / recover it.
I will re-register as a Mudcat member so that you can contact me directly.
I think I could also remember the "simple chord" version I worked out by ear in my youth, if that would help, but I imagine you already have worked out something similar.