I was going to meetings as a kid during the 60's and baptised in the 70's - UK.
In 1967 there was the world's first heart transplant (Christiaan Barnard South Africa) which brought into focus the witness view. But of course kidney transplants were becoming more common too.
As mentioned above it was generally viewed as cannibalism and linked to blood transfusion (as in back then you would "obviously" need a blood transfusion if you had a major organ transplant) and QFR in 1967 was weighted heavily against it as were small references between then and the QFR of 1980. I cannot say if it would have been a DF offence as I was a baptised teen with no appointment in 1980. (I always thought it was but can find nothing in the WT CD library.)
But my understanding was that it was definitely "wrong" because the articles were disapproving but I can go no further than that in what if any the sanctions might have been.
The way it was "fed" to me by elders at the time was that it was a "no-no".