La mansión de la niebla (1972)

[mortimer]

I add some missing people and different shots of the unidentified cast.

bar customers and barmaid

close-up of the party guest dancing with Gadé

Adelina, Elsa's Father's lover

Maybe the credited Maria Reniu?
She actually is listed only in the opening credits with no role and not in the closing ones, where there are only 4 hotel guests reported, how many in fact are.