Question1: if a HQ 1 tonner cab with HQ tags from 1971 go onto a late WB chassis from 1984, what ADR's does it have to comply with?

Question2: If your answer to question 1 was the WB ADR's, how would some inspector at the inspection station know if that chassis was a 1980 chassis or a late 1984 chassis? and hence 1980 ADR's or 1984 ADR's?

Question 3: why wouldn't the 1 tonner in this configuration have to comply with the ADR ID tag on the cab, - the 1971 HQ ADR tag, as there is no WB ADR tag in sight......

Question 4: why are HQ 1 tonner compliance tags worth more than all the others???????? hint - pre pollution Chev.