Hi Jeff-
The Ardevol was published by the Pan American Union in DC; Peer International Corp. was/is the sole selling agent. It might be completely out of print by now. My score is pretty old (and the purchase price said $3.25
) I'm not sure where I picked it up - quite possibly some flea market!
I think the Casella was available from Boosey & Hawke when we did it - but it might be rental only at this point. I'm afraid that concert was over 10 years ago, and I've forgotten a lot of the nitty gritty details about where we got parts. I'll see what info I can come up with tonight.
Best of luck with the article - sounds like you've gotten lots of good pieces to put out there, at least!
Sandy