Do these adjust elevation by turning a screw as the name implies, or are these the type that you loosen then slide up and down to adjust?

They adjust by turning a micrometer click screw.

And I think (IIRC) they came with two different kinds of knobs to adjust them.... the buyer's choice of either "Target knobs", which have knurled heads on them and are turned with the fingers...or "Hunter" knobs which are slotted to be turned with either a dime or a screwdriver.

I always preferred the Target knobs, but some folks like the Hunter knobs better, because no one could just fiddle with them in passing, in hunting camp or in your gun room.

They also came with the buyer's choice of a "long" or short" slide...the long slide providing greater elevation adjustment for long range target shooting. On hunting rifles I preferred the short slide because you don't have to cut near as long a slot in the side of the stock for the slide to go up and down in.