BPJack and campfire: Your Centaure is a Regular New Model Army (RNMA) 2nd variation 1st sub-variation: 3-screw frame with notches in the recoil shield and a toe on the butt for the attachment of a shoulderstock, 8" barrel. Assumingly 7 rifling grooves.
According to the serial number she was made in 1963.
The hammer is period correct of the 2nd version.
The barrel marking most likely reads "1960 NEW MODEL ARMY" CENTENNIAL TRADE MARK CHICAGO U.S.A.
Your #2570 is fitted with a cylinder with the so called Centaure proprietary naval engagement scene. It is similar to the Ormsby scene but has less background details. It was roll-engraved at the Belgian factory which is in contrast to the RNMAs of the 3rd variation with the Ormsby naval scene. The latter was applied at the shop of then main distributor Centennial Arms Corp. of Lincolnwood, IL, U.S.A.
Among other proof marks of the Liège proof house the left side of the barrel lug and frame and the cylinder carry the inspector mark * over U sideways. It was the mark of one Jaques Fuchs. Fuchs served at the proof house in this function between 1960 and February 1968.
These Centaures look from the outside like the real thing with many parts being compatible.
Their Belgian makers had a production license from April 1853 by Sam Colt himself to produce Colt percussion revolvers to certain standards. The license was never terminated.
The Centaures were constructed between fall of 1959 and early summer of 1973 as rugged target revolvers. Hence, the diameter of their rifling groove diameter is adjusted to the chamber diameter which is .446". Hence the recommended ball size is .451". The rifling is a modern shallow one. These two factors combined mean less gas leakage and a flatter trajecory compared to 1st gen Colt Armies, Italian clones incl. 2nd/3rd gen Colt Armies. No offence meant!
Particularly the cowboy action fraction competing with percussion revolvers like them in Europe if they can lay their hands on a well maintained pair. Many of the variants are sought after by Centaure collectors including your RNMA 2nd var./1st sub-var.
Without a physical to check functioning incl. the condition of bore and chambers I hesitate to quote a value.
Anything else you want to know just let me know.
Long Johns Wolf
