Created attachment 465054 [details]
As it turns out, the freepats are now located at http://freepats.zenvoid.org/ instead of http://freepats.opensrc.org/.
This updated ebuild for the =media-sound/timidity-freepats-20060219-r1 package is tested and working on my system: I was able to play back a MIDI file in timidity++ without issue, and the ebuild satisfied timidity++'s dependency even when placed in a local overlay.
There appears to be a new collection of instrument patches released just this month, but I have not yet developed a working ebuild for them. For the time being, I would like to submit this ebuild so the mainline timidity++ package remains usable with free software.