Glad to hear you pulled the trigger and gave BUB a new home. It looks like a lot of attention (and beer !) went into his build.
Fortunately, fairing is easy to do (though monotonous) and you'll pick up a feel pretty quickly. Those are all flat panels, so a long sanding board, some epoxy, lots of microballoons and you're off to the races. Those cheap yellow plastic putty knives work great for spreading and leveling the goo.
As far as your door goes, if you drill the #8 holes out to say 1/4" and glue in dowels, can you then use screws to hold the hinges rather than bolts ?
Or maybe threaded rod with nuts on both ends if you can't find 8-32 long enough ?
Normally, you would go to a bigger (thicker) bolt if you need one that long: #10-24 might be available that length, but I know that 1/4"-20 are easy to get in 4" lengths. I use a lot of them (stainless) for securing equipment to the decks of boats.
Just want to add one thing to norm's post about cutting bolts down: if you thread a nut onto the bolt before you start, you can back the nut off to restore ('chase') the threads that get distorted.
Just a though as far as the door goes...looking back a page or so, GPW posted a drawing of the round door filled in and squared on the bottom as sort of a 'false' round door. Something like that might let you mount your round hobbit door in the top part of the shell and have a 'filler' door in the bottom part. A couple barrel bolts and they're locked together. The lower door could use takedown hinges so you can remove it when you're folding it down to make it accessible through the main door will collapsed.
These are polished stainless marine ones and retail for a little over $100 a pair, but they ought to be available for cabinetry as well.

Poison ivy...ugh.
I picked some aloe gel that has lidocaine in it: it works great on all sorts of burns and bites. We've had such a cool wet year so far the mossies are eating me alive so I'm going through quite a bit of it. I blame Noah for bringing mosquitos onto the Ark in the first place.
