There was something about displaying body parts, in another legislation. Offhand I can't recall which it was, but as they were in a private house and not on public display I can't see that working either. The stated case involved somebody showing a passenger, a skull in a railway carriage.1982 or 83, I was still a probby.
The 1984 legislation came about after an enquiry found that many undertakers and mortuary staff were making money off the dead. Theft of clothing and watches and jewellery from the deceased, organs, prosthetics for re-sale. Even pathologists and coroners were getting cash from it.