Standard test No. 1:
Q. Is there a postal address given on the website. (It's a legal requirement for UK internet traders)
A. No
Standard test No. 2:
Q. Does the company use its own domain name (i.e. the bit after the '@' sign) in its email address, or does it use an untraceable wemail service, such as GMail or Hotmail (which is both 'unprofessional' and 'highly suspicious')?
A. There are 2 email addresses. One is with GMail. The other is with Hotmail.
Standard test No.3:
Q. Is there any way at all (even if there's no postal address) of contacting the firm, other than by email?
A. No. (The absence of a landline phone number, or even of a mobile one, isn't actually illegal but it's worrying).
Standard test No. 4:
Q. Is the domain name (raretvondvd.com) 'hidden' in any way?
A. The name is registered to the Cardiff based firm which created the website, rather than to the company owning it. That's not particularly 'suspicious' in itself but it certainly suggests an 'unprofessional' way of doing things. Most reputable companies ensure that their domain name is registered to their own company.
I'd also query the source of the recordings they're offering. They appear to be copied from American VHS tapes, in the NTSC format. I would very much doubt that the firm has a licence to make such copies. (If the people who own the rights to the programmes wanted them to be available on DVD they would have issued their own disks, using the original master tapes, not VHS videotapes!).
Chris