If the tooling still exists, the cylinder was chambered for 45 Schofield, and the frame, and particularly the top strap, where the right length for a 45 Schofield length cylinder. By the way, the 1 7/16" long cylinder is the reason the original Schofields were chambered for what was then a brand new cartridge, the shorter S&W Schofield cartridge. A cylinder that long could not accomodate the longer 45 Colt round. It's along story I will explain some other time.
If you want the same revolver chambered for a 'modern' cartridge' like for instance 45 Colt or 44-40, which are both actually older than the 45 Schofield round, the original tooling simply will not work with a longer round.
This is a first Model Schofield that left the factory in 1875. The arrow is pointing to the bushing on the cylinder that protects the underlying cylinder arbor from Black Powder fouling blasted out of the barrel/cylinder gap. When fouling blasted out of the b/c gap lands on the cylinder arbor, it tends to bind up the cylinder after just a few shots. The cylinder bushing is pressed into the cylinder, and it provides horizontal separation from the b/c gap and the front end of the cylinder arbor.
View attachment 983063
Now go back and look at the Schofield Model of 2000 in the original poster's photo. There is no bushing visible at all. S&W changed the design for that version, they did not intend them to be fired with Black Powder. And if somebody tries to shoot one with Black Powder, the cylinder will bind up quickly because fouling blasted out of the b/c gap will build up on the unprotected cylinder arbor. My point is, in order to fire a longer 'modern' cartridge such as 45 Colt, or just about any other cartridge you would care to name, the cylinder would have to be lengthened to 1 9/16", and the frame stretched an extra 1/8" to accommodate the longer cartridge. The original tooling will not allow this. During the 1880s, S&W made some longer frames for their New Model Number Three and 44 Double Action to go along with a 1 9/16" cylinder so the revolvers could chamber 44-40 and 38-40. S&W never chambered any of their Top Break revolvers for 45 Colt.
By the way, when Uberi began making their version of the Schofield they lengthened the cylinder to accommodate 45 colt and 44-40, but they did not stretch the frame a comparable amount. They instead chose to shorten the bushing on the front of the cylinder, which is why Uberti replicas of the Schofield bind up quickly when fired with Black Powder.
I seriously doubt S&W is listening anyway, their bread and butter these days is semi-auto pistols.