WidDunesDavid,
I'll try my best to help. I've only been sailng a 16 for a couple of summers, but I may be able to help with some things. The best place to start for replacement parts is here...
http://www.hobiecat.com/support/tech/h16parts.html
It is a parts diagram for your boat. You'll also want to order the free catalog here... It's filled with TONS of great stuff.
http://www.hobiecat.com/sailing/accessories.html#catalog
As far as the shrouds go, you'll want everything pretty tight. When you're sailing the leeward shroud will be a little slack, but when the boat's on the beach all three should be pretty tight. I don't really understand what you mean by "close up the shroud anchors in the hull." And what bushings are you talking about? Let us know and we'll do our best to answer.
jrg