Lousy pics...but Felt Insulation under dash
at least you can find some evidence that I'm not entirely off my rocker...
Your piece on the top right, is glued to the left hand side (I'll not use driver's side now ;-) under dash crossmember / bulkhead under the dash. You'll see it with the first pic (Ti.LH.insul.sml). In my image, the portion that is hanging down should be glued up under the bulkhead. The 'slit' is there to prevent the material from bunching as it folds and adheres under that crossmember.
The other pieces are harder for me. I know the lower right piece goes directly on the firewall (under the very top of the false floor area for LHD cars), and leads up to near top of firewall. The hole did not really line up with anything under there from my view. The harness did not go through the hole, but rather to the edge of the insulation. (pic added) These pics (Ti.RH.insul.sml) are very difficult to understand, sorry. But, the wide portion is arranged at the bottom / down, with flat (parallel) to floor, and holed narrower portion at top.
Can also see Gary's mention of the square piece in heater blower location.
Unfortunately, I just can't locate pictures of the other pads. Will keep searching. That 4th piece is a unique animal in my book. Not the same weave. Neat find / keeper.
I failed to remove all of these pieces prior to media blast. I had not expected them to 'shoot' under the dash. I also failed to ask them not to remove factory insulation from rear shelf area. Both big things that I blew with poor communication. Learning mistakes...
A bit astonished you've not received a better response for the request for 'original under dash picture' from another member here...
(search keywords: felt insulation)