I have absolutely no idea how I found this film, probably a night of drunken Amazon surfing - I've bought many strange things doing that!
Anyway, 'Santo & Blue Demon Vs. Dracula & the Wolfman' (what a title!) is pretty much a regular monster flick (similar to a Hammer horror movie) except the heroes are a couple of Mexican wrestlers who, when not wrestling, act as detectives (wearing the mysterious wrestling masks at all time).
The most bizarre thing I found about this was at intervals during the film there would be several rounds of wrestling. These scenes rarely have any relevance to the overall story but are fun nether the less (the commentary is hilarious).
This film is part of a series of similar themed movies which usually feature the title of, 'Santo Vs. *enter monster name here*'. Santo is one of Mexico's most well known characters, often compared in popularity to James Bond (007).
Here's a clip from the movie, Santo wears the silver mask by the way.