I don't know anybody who wouldn't be happy with a 2o year old factory 30-06 that shoots that well. Heck, I don't know too many people that wouldn't be happy with any factory rifle that shoots that well...and those people would be on this board!
I too would bed the stock and do something with the trigger. The bedding will keep it consistent. Getting trigger work done is like mounting a scope on a rifle, it doesn't make the rifle more accurate it makes YOU more accurate. Start loading your own if you don't already. Start with a clean barrel (if you don't know how fouled your barrel likes to be) and fire a few fouling shots before shooting for groups. I'm sure you'll get more good advise, but it sounds like you are asking for a lot out of the old girl. I mean come on, she is already capable of under 2" at 300.