I need your help to put my truck back together!

[budman k20]

Hi,

I'm trying to put my freshly painted 72 K20 back together...but a couple of small items are holding me back! First where do you find a new brake rod boot? The one that fits in the firewall. Bob's chevy parts lists them but they don't have them anymore. Tried NAPA no luck, also as far as I can tell the usual suspects don't have them either. Help me out where do you guys find them!
My next quest is for firewall insulation fo an AC cab... that also seems to be a non exisiting part. What are you AC guys doing? Making a template and cutting one from an extra center piece or what?

I did use the search tool but found no mention for either of these. Please help I need get this thing on the road and get some rock chips on my new paint!