I had some misc. parts on order to replace some less-than-optimal hardware and decided to knock that item off the to-do list today. I replaced the AN4-4 bolts that were holding my two regulators in place with 4-5 and now there are 3 threads showing which was better than the 1/2 thread I had showing before. I turned the bolts around as this should be the last time I fiddle with these bolts and now the "more" flush side is in the baggage compartment. I also replaced the two screws on the parking brake valve as they were not long enough.
After that, I installed the cabin heat box with the stainless-steel bolts, washers and nuts - but only after sealing around the pass-thru hole with the supplied Biotherm 100 silicone firestop sealant.