Does your rifle have e/77 on the right receiver; have you a picture of the siderail?
That it has 4 digit serial and a suffix underneath means nothing negative, it is proper, it just means it was the 148,037 rifle made in 1943, - though not necessarily accepted (final inspection). Each letter block, starting with "first block w/o a character" is 10,000 rifles, SDP serialed every block, including "i" and "j", so by the "n" block it would be 140k plus the rifles serial number. Serialing was done early in the process and they didn't back fill serials for rifles that failed along the way, but the short of it is this was the 148,037 rifle SDP assembled.
Because it is an rc, little more can be said about it, though the receiver was made by Steyr-Radom and most of its original metal components would have as well. The only parts the soviets would have kept are the barreled receiver, including the front sight and rear sight sleeve, which probably are e/77 components. The barrel is original to the rifle and the only part actually made by Steyr in Austria.
Unfortunately, when the soviets "refurbished" the rifles they crudely refinished the metal, and that hurts collector value to most collectors.
Someone questioned the 4 digit serial number with the "n" under it. Didn't know what that meant.