Re: Is This a Remington Revolver ?
I have an original New Army Model 1858 and it has the serial number on the trigger guard tab and on the frame under the grip, where yours does. However, they are very faint and in the 50,000 range. I understand that Remington records were lost or destroyed years ago, but there are records of batch shipments showing when groups of arms were delivered to the government. Those records show mine was shipped in 1863. I suspect these are the "batches" you are referring to--proof of delivery but not actual manufacture. Reproductions were being done (for Colts at least) as early as the late 1850s in preparation for the 1961 Civil War Centennial. You can check to see if those grips are actual Ivory and not a plastic "ivoroid" substance--check the internet for how to test--if they are ivoroid, it is likely a reproduction. I believe (but please check) all you do is heat a needle red hot and apply it to the back of the grip where a mark can't be seen. If it melts and smokes, it is plastic. Also, some of the frame contours are incorrect--there should be threads showing where the barrel protrudes through the frame and meets the cylinder.
I agree with Jim--I have never heard of any northern company manufacturing Remington clones.