Indeed. I have had as much of a skwizz of said 'Act' as can be borne by any reasonable man (ie not much) and have concluded that i can't really be bothered to explore it any further.
The geezer with the DVDs for sale is basically selling a copy of the YouTube download above. I think he may have a point in that this was a TV movie that wasn't on general release. I have read on another site that this only exists on a '00 VHS' tape of some sort so is almost certainly a video copy of a made-for-TV movie.
Interestingly though, i definitely (i haven't had the time to watch it yet, so i can't really be quite so definitive, yet i'm absolutely definite that i...) watched this in a movie theatre, and at a time when the digitalisation of anything at all was some decades off. This would suggest, if not insist, that there was at least one cine reel version of this film.
If i had to place it in time, i would guess at circa 1979 when i viewed it. The cinema in question was not particularly known for the contemporariness of its offerings - the fact that i saw
Jaws in the same theatre, which was very much the exception that proved the rule for its lack of contemporariness, would tend to support such a date. One of the great things about this particular theatre was its love of money above its duty of care to the classification system of the films it showed.
Either way, i doubt anybody connected to the film is likely to give much of a (parrot) shit.