Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
Yeah those bolts were only fitted to the modified rocker covers. It was meant to stop the rocker shafts spinning as they were elongating the hole they sat in.
You can take the valve stem seals out with long nose pliers . Sand in the head? you should of got it soda blasted. Now you must get every grain out. A couple of grains stuck in a oil way will destroy a bottom end.
You should always clean a engine before working on it. Unless you intend to do a full strip and rebuild.