Quote Originally Posted by jaft View Post
was that for just that month only and was that all plant...

cheers mate
It appears any of the plants still assembling Panel Vans after May/June '74. So if you spot a HQ without side air vents it is likely to be dated 6th, 7th or 8th month '74.
No HJ's ever had side air vents I believe. It was a design change late in the very last of the HQ's and then onwards. I say it's because of the change to HJ bodies. Byron of course has a different opinion.