After studying various aspects of this car, I can't say for certain what it is, either. I'm no expert, but there are just too many parts of it that don't point to any one coachbuilder:
1. Notice how at a distance, those look like the landau irons used by S&S and B&B, but a close look at the video reveals them to be "peaked" lengthwise in the arms, not flat like those found on S&S and B&B cars.
2. This obviously isn't an S&S, but the "step" at the rear beltline, along with the close imitation of the landau iron style, indicates that soembody was attempting to duplicate some S&S styling on an economy coach.
3. The exterior styling of the rear door throws me. While it does utilize the standard station wagon tailgate handle (like B&B and C&C did), the sheetmetal styling is different than anything I've seen before. One would expect it might just be "flat" like the standard wagon tailgate, but this one has some contour to it.
4. The drapes are too "frilly" to look like anything from Demers, B&B or C&C.
5. The short ledgeboard trim boxes (over the wheelwells) in the rear are interesting and unique, along with the button-tufting on the sidewalls. Again, this doesn't really scream B&B, C&C or Demers.
6. Alberter was trying to be a major player in 1988, especially with tail-stretch cars, but this is obviously not an Alberter, either.
My guess is this car is the product of a very small shop soemplace that attempted to cobble up an economical hearse. For what this is, it looks like they did a very nice job. I'd love to see this car in person.