Tom
Welcome to schuetzen. I hope you find it as fascinating as many of us on this forum who have been in the game for years.
The key word in your inquiry is traditional. That book's emphasis is on loading and shooting traditional type rifles, for which a barrel clamp front rest is appropriate. At some risk of over simplification, there are two camps in the schuetzen game. One camp shoots rifles that retain the look and feel of those used during the original schuetzen era, i.e., original or reproduction actions, splinter forestocks, tang peep sights, scopes with external adjustments, etc. (both the ASSRA and ISSA have rules governing traditional rifles). 
The other camp tends to the more modern actions and modern internal adjustment scopes, etc., this is the Open class and also has its set of rules. In the Open class, it is almost standard to have a wide forestock for bench shooting like those you are familiar with. There is no right or wrong of either of the two rifles classes, they just are.
The bench technique of which you write will serve you well in shooting an open class rifle. A traditional rifle my require a little more finagling to refine your technique but is essentially the same as what your are used to.
Included are two photos of the same rifle, top is set up for traditional and bottom photo for open class.
I hope this helps, at least in a general sort of way.

Tom
The front bag is firmly filled and the forestock is squeezed by the front bag but the rifle has been slid back until stopped by the pistol grip contacting the rear bag. This helps me keep the whole rig from moving while breech seating a bullet.
The barrel clamp setup slides back on the platform with that bar as a preventer keeping the clamp from coming off the platform rear. The platform has a peg on the front edge and the barrel clamp a V notch, so the rifle goes back into battery each time.
In either setup, I don't completely let the rifle free recoil. I place myself on the gun so that the butt plate stops on my shoulder after about an inch of recoil.

Thanks 40 Rod.  I must agree with you on reading the wind!  The two hardest things I found in hipower benchrest were setting up the bags properly to make return to battery easy and then picking the condition for the first shot for score.  Not being a machinist by trade where would one look for a sled and clamp arrangement to buy?  My feeble mind has been trying to design something using a block of delrin as a base cut to fit in my current rest if I remove the bag and bag clamp.  Tom

"bag squeezer"
That's the way I shot bench rest with an offhand stock years ago. It was always a bit unpredictable as your hold consistency has a lot to do with accuracy. One technique that used to help controlling the rifle was holding the buttstock with your left hand at the point of cheek contact instead of squeezing the bag, plus using light contact with your right hand on the wrist. The two piece stocks of our single shot rifles makes the wrist surprisingly flexible so it does not take a lot of cheek pressure to flex action enough to effect bullet impact.
Now I use a barrel clamp front rest, no cheek contact on stock and overall accuracy is far superior. As an example, once in a while I shoot a 250 which had eluded me until I began using a barrel clamp front rest.

I returned to shooting off a bag several years ago and I had David at Protektor make me a custom bag that fits my barrel and I also increased the surface area the barrel rests on. The front bag is filled half and half with parakeet gravel and heavy sand that seems to have better control over the barrel harmonics. Also if the front bag was to hard I would get noticble barrel jump. Back bag base is rock hard the ears a tad looser. I do rest my cheek on the stock and cradle the butt stock with the thumb and first finger of my left hand. When I am shooting good it is because I am totally comfortable and relaxed. Extremely relaxed would describe how I hold the rifle, the cheek pressure, upper arm resting against butt stock and centered in the hooked plate and I place my thumb very gently on top of the pistol grip. My barrel likes being seated in the bag directly in front of the forearm and it is used as the return to battery stop. Rifle is a 32-40 CPA Schuetzen Jr., some refer to at as a model 52. Front bag is 6" wide, 5" in depth, barrel channel is 3/4" radius 1 1/2" deep and the bottom of the channel is 1" from the top of the mounting plate.

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Well, John, your description of technique sounds much like my own method. Or, what I try for at any rate. My hand is not on the stock, but on the lever's side. My front bag is not as low as yours lets the barrel rest. I use mine for any rifle I shoot, so not made for just one. Store bought rough leather. With talc.
Sometimes I just dispense with the rear bag, and don't see much change. This description is pertaining mostly to a single rifle that's been my latest challenge. Maybe I ought to stop the coffee and switch to brandy for relaxation. Could be closer to the truth than I realize, huh?

Again a picture is worth a 1000 words.  I can see how the barrel is clamped into the sled but how is the sled held in alignment on the rest during recoil and then returned to battery?  It appears that the notches must straddle something on the rest and that the V is for a positive stop.  Does it make a difference how close to the muzzle you clamp?  Tom