Luis Gaspar, Miguel Rellán, Rafael Vaquero and Jesús Alcaide have all been identified and added, which only really leaves
Amparo Valle as someone who could, in theory, be identifiable. Valle seemingly belatedly became quite well known on television from the 90's onwards when she was in her 50's/60's, but all the images of her online date from this period and trying to identify her in earlier roles was difficult. I think this may be her on the left in Pim, Pam, Pum… Fuego (1975), but am not absolutely certain.
Valle would have been aged around 40 when this film was made. Of the few actresses in the film the only 2 who appear to be of an appropriate age are the 2 below. The first one I suppose might be her, but I'm struggling to convince myself.
Given the apparent non-appearances of familiar credited actors Rafael Albaicín and Luis Barboo, it could be possible that there was a scene cut from the film where these actors appeared, which could also account for Valle's seeming non-show.