I've had a lot of experience with those 305's; be real careful getting the petcock bolts out - I think they have a 5.5 thread, very difficult to find, IIRC. Also, those OEM petcocks are (1) expensive, and (2) pretty leaky, even with an aftermarket kit.
On the other hand, they sound like a Harley and pull pretty well! As far as the shocks, you could always just spray the red (plastic) part black...?
Oooh, and I see you have the Very expensive and hard-to-find carb cover! Those chainguards are also very hard to find in two pieces, as you noted...
Also, there's a hack somewhere online to make a replacement air filter out of a Fram air filter, using the original air filter housing; all you need is a heat gun to get the old glue/filter out, trim the Fram filter out of its rubber lining and then epoxy the new filter in; I've done it, it's not too hard and looks brand new when done.
Harbor Freight also sells a copper washer set for about $5 with a variety of different sizes and one fits the top engine bolts perfectly.
Here's the one I did:
DSCN1262 by
Dr. Frankenstein1, on Flickr
Here's the 'Before' pic -
As I Got It by
Dr. Frankenstein1, on Flickr
Here's a black one I did; it's a '63, and I got it mostly for the very rare no-seam gas tank, but it was in such good shape inside I decided to go for it:
DSCN1056 by
Dr. Frankenstein1, on Flickr
DSCN1064 by
Dr. Frankenstein1, on Flickr
It didn't turn out too bad - I didn't even really need to mess with the engine too much, it cranked up as soon as I got it sorted. I wound up selling it, and wish I hadn't. I also just discovered it for sale on Craigslist too! Oh well...
1963 Honda CA77E by
Dr. Frankenstein1, on Flickr
So, yeah, I kind of know my way around those bikes. Watch out for those aftermarket wiring harnesses though; there's a few wires in them that are not needed, and will make you scratch your head. The shift-shaft is a great place for oil leaks; and if you lose the key, you can use a screwdriver to turn the 5-position ignition.