Richard, I have accurized a few MK-II, This is what I do to them; Trigger lightening to 2 lbs. Epoxy and /or pillar bed, with the barrel free-floated. Cut a new crown concentric with the bore. Lap rings and remount scopes. Those guns that I then develop a hand load for have shot 3 shot groups in the .2-.5 with the factory barrel. I have not messed with the plastic stocks, these have all been wood stocked guns. I think free-floating along with scope ring lapping eliminates point of impact shifts. Ruger makes a good ring mount system, but rarely do the two rings line up properly. I will always float a barrel in a wood stock to eliminate shifts due to pressure point changes. I think the hand load is key to finding good accuracy with the MK-II.
As far as you question about glass bedding the action, if not using pillars, I wrap the barrel near the forearm tip with tape, to hold it centered in the barrel channel I opened up. I dremmel into the wood, some locking grooves and holes under the tang, and action flat around the lug. I use enough epoxy to get a solid bed under the action, and under and around the tang. I do not want the epoxy to squeeze up the sides of the front of the action more than a 1/8- 1/4 inch or so, if it squeezes all around the action sides it is difficult to separate the action from the stock. Other than that similar as a remmy, just a touch of grease on the bolt threads so they don't glue in.