It is an interwar 98a, those are sure signs of it.. next, at your leisure, take the handguard off and examine the serial number. Incredibly unlikely this is the original HG, but also look at the barrel, typically they are original to manufacture, it is rare to encounter a re-barreled 98a, but they do show up from the interwar period. Typically when they are seen they are recycled 98a barrels or ordnance spares, as I do not believe they made 98a barrels in the interwar period, though they might have made a few very early. You can find them with Weimar eagles and interwar markings, including police acceptance, but again quite rare.
Anyway, while it is a general rule that interwar reworks take a hit on value, it is less so with 98a carbines, especially so with one such as yours where the signs are subtle.
** I would also suggest you examine the stock closely for small acceptance stamps, especially at the wrist and all around the buttstock. If you are lucky, it will have an interwar depot marking, that would help value a little. People like certainty, and things like acceptance are a plus. I assume the buttplate has no other markings, or you'd of shown them, but take some time to examine every surface of the stock for stray or unusual markings. You seem to have had a little bit of luck on this one, VERY often the depots sanded the stocks and often replaced parts, this rifle looks fairly original, with only minimal work done, the follower (which is almost universal, I have never seen an interwar G98 or 98a without a blued-notched follower, but I have seen rifles without the extra band serialing, though rare) and bands look like the extent of the work done. Of course there is the RS part replaced, the m/m bolt, possibly the HG, but the thing with interwar rifles like this is "most" are a lot worse off. It is pretty difficult to find a fully matching interwar rifle, especially G98's...