Some Mexican companies put English subs (and, sometimes, French as well) on their DVDs. As an example, this edition of "Santo en el museo de cera" (Samson in the Wax Museum). The quality is excellent (superior to the Santo series made in the USA by Rise Above Entertainment for instance) - without speaking of the movie itself which remains one of the better Santo, with a splendidly malevolent Claudio Brook.
The website is www.alterfilms.com
According to the trailers included in this DVD, many of their releases have English (plus, sometimes, French) subs.
I found this one on eBay and the delivering (Mexico to France) was very quick.

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