I Think Both Descriptions Are Accurate
From the way it's described the two concepts, a mad scientist trying to resurrect his wife and a series of movies hosted by a mad scientist, don't seem to contradict to a huge degree. I think a possibility is, like say Tales from The Hood, it may have had a major wrap-around story with this "Mr. Sardonicus" type mad scientist trying to resurrect his wife while narrating scenes from previous movies, perhaps with the idea the previous movies were "true stories" or something. There was another movie, an anthology horror movie, that did this where it had several stories with a major wrap-around, and it's similar to Body Bags also. So I think this movie probably did exist and may have been a kind of inexpensive, one-off anthology film or Greatest Hits movie for Lugosi.