The biggest difference between the 1898 and 1896 stock is the scallop cut around the bolt handle, or more specifically around the trough the bolt handle passes through. The 1898 did not have this trough. 98 left, 92 right, but the 96 is the same as the 92, a little wider perhaps.
I think the earliest 96 rifles were the Cadet rifles made for West Point, they were done, in my opinion on 1895 dated receivers with their serial #s in the 24,000 range. And, they were different from regular model 96 rifles. Other than those it appears the earliest 96 rifle would have been around serial #36591, based on some that we know of now. We may not have that exactly, lots of missing numbers.
Ah, now I see, the first digit of your serial # may be an 8. Hard to read, 3s and 8s are sometimes hard to make out. If it's an 8, then it fits right in with the rifles.
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