Here's a link to an early A-bolt for sale. Look at the photos and you can see the fluted bolt. Armslist
That ad is wrong about one thing. It says that is a 1981 A-bolt, but the A-bolt was introduced in 1985. Before that was the BBR - Browning Bolt Rifle.
Just looking at the photo, it appears that the A-bolt I didn't have the non-rotating bolt sleeve that the II had (and which made it so smooth to operate).