I posted on this topic over thirty days ago and when adding to it tonight got a pop up message suggesting i start a new post. So I got some ideas, which i have followed from replies to the older post.
Tonight I have removed the instrument cluster but this did not help. I have also removed the wood bow on top of the vinyl dash top, and the vinyl dash top itself (see attached photo), but this has not helped in accessing the blown bulbs in the vent/heater lever control area themselves. I can see some of the round black boxes, with wires leading into them, that one of the replies suggest but can't access them through the hole in the top of the dash.
Any other suggestions?