Thomas Weisser writes in his book Spaghetti Westerns: The Good, the Bad and the Violent that “[i]n 1978 an unscrupulous production company secured the rights to tDPF, and after inserting hard core sex scenes re-released it under the name Porno Erotic Western”. But in fact, Lo ammazzò was re-released in 1979 in an extended 90 minutes’ version with 14 years rating (English title Requiem for a Bounty Killer ), while Porno Erotico Western was released by Pannacciò himself the same year. According to Maurizio Centini, the cinematographer of the latter film, it consisted of scenes from two westerns Pannacciò had produced in the early 1970’s (that would be Lo ammazzò and Una cuerda ) with additional “pushed” scenes (“di scene spinte”) shot by Pannacciò at Gordon Mitchell’s western town.
This I think now can be laid to rest.