I had privelage to have personal contact with Brian Jones chief engineer at Triumph Meriden, the worker's cooperative and LF Harris. For 5 odd years Coventry Spares Ltd traded as LF Harris International here in the States. I used a lot of that time asking him questions. One that still stands out was the answer he gave when I asked him about the valve stem clearances listed in the workshop Manual, "I have never looked a Workshop Manual." I told them what they were and he answered, "That's not right."