Bill's right about TDA never venturing into Iron Butterfly territory. But a quick Google search reveals that many accordion players and squeezebox-toting bands have played that tune that I can't be sure I can spell correctly.
After some digging, I did find that Brave Combo covered In-A-Gadda-Da-Vida as part of a melody with another song. It can be found on thier album "No Sad Faces" (circa 1984) which is probably out of print. But you could try contacting the band through their website: http://www.brave.com/bo/
It might be available as an mp3 download someplace on the web that the band can point you to. Or you can try searching the used music outlets online. Someone on eBay might even have it.