edit: assuming it's in one of the collections we're currently testing on. (all the opensource_* ones) (etree and netlabels _should_ be all torrentized [we hope])
i don't particularly want that album (i probably already have it thanks!) but it doesn't mention a torrent that i can see (the etree files have torrent in the links). and that's the same for all netlabel files (not many) that i have checked.
in comparison, http://archive.org/details/SPBB2006-04-29 (bluegrass etree!) does have a bittorrent link (bottom right).
i don't understand your opensource_ comment, but pueblo nuevo is a netlabel. so it seems to me that etree have torrents, but netlabels do not.
(this is just in case it helps / it's likely i am confused / no criticism intended / thanks for doing all this)
ah, ok, so if it's a torrent it's listed as such in the download links.
and it's the etree collection (the concerts) that seems to be what is available. you can search with "collection:etree" in the search. so "bluegrass AND collection:etree", for example.