John, they are a laminated stock which I personally despise but some people love them. Each to their own. You could add a recoil reducer or maybe two into the butt but then it upsets the balance noticeably if the stock wasn't built with a recoil reducer in mind from the start.
Ross Waghorn charges $3k for a bolt action stock plus wood which is made from a solid blank, he will not use pre-inletted blanks. About $4k if you want a cheek piece as well. I would guess that stock makers in England would charge similar. While it adds to the original purchase price it will actually do what you want. If it doesn't fit and beats you up every time you fire it then you end up selling it quickly so it ends up a waste of time. Better to spend the extra and have a rifle that you like to shoot.

I would like to add another one to my 505 in the butt (It already has one) and then fit another smaller one in the forend. The thing you have to be careful about if fitting one to the forend is they have a tendency to split the wood, however on the CZ550 there is a very large recoil block integral to the barrel so I will try to mount it so that it rests against that recoil block.

With the CZ550 the barrel is profiled instead of having a straight taper like the original 505'S and 500 Jeffery's so it looses some weight there. I believe that once the stock is reshaped and the extra recoil reducers are added it will be easy to shoot.

Matt.