I am trying to understand something about Rem 700 rifles. I saw them with two cross bolts in the stock, like this example

http://www.gunsamerica.com/use...55730/wm_6666261.jpg

And with one cross bolt, like the current ones

http://www.remington.com/~/med...BDL/700bdl-prod.ashx

And with no cross bolts at all in older ones

http://media.liveauctiongroup....pg?v=8CF5F35E2065320

Makes me wonder, are these even real cross bolts at all? Why no holes in these bolts to unscrew them? What is the purpose of them?

What you are seeing there is plastic plugs, not cross bolts. Under the plug is a wood screw.

Also, some 700s had a brass pin inserted in the area behind the mag and in front of the trigger/bolt area.

By judgment of the recoil pad on the first rifle it must be an Ultra