Listening to this on a seven inch single and trying to figure out the true story. On the YouTube, guitarist Joe Maraia comments that it was his band The Questionaires under a fake name. But Warren Schutz, the song writer was a Brill Building guy and so my assumption was that it was session musicians doing it especially for the film Unholy Matrimony (a super cheap exploitation b-movie). Which is backed up by the acetate by Maraia's band, on YouTube, sounding quite different from the released version under the Warmest Spring name. I've found Shutz on Facebook but I think I'd feel weird to message him and ask him about it.