I have made some great progress since my last post. First, I punched through one of the freeze plugs. I used a tapered punch so the hole would get bigger the farther in the punch went. I made a big enough hole for a threaded rod about 1/16 of an inch smaller than the ID of the shaft. I stuck it in the shaft and punched out the opposite plug, then removed it and punched out the other one. It was pretty simple. I then used a wire to poke out the oiler holes and also used that same threaded rod to push paper towels through the shaft. After about 5 or 6 runs, it is looking pretty clean.
Freeze plugs: http://good-times.webshots.com/photo/2749225940100058208LBKTWu
Rocker shaft: http://good-times.webshots.com/photo/2679261390100058208bzJXdu
Not a very good picture: http://good-times.webshots.com/photo/2061608520100058208EJEhkQ
Method of cleaning: http://good-times.webshots.com/photo/2316390950100058208KNriov

http://community.webshots.com/user/justinsquire