These are great rifles. One of the best kept secrets in the rifle/shooting/collecting world. I have two; one in 8x57 and one in 9.3x57. Mine are both commercially made Husqvarnas on the 96 Swedish Mauser action, models 640 or 648 or 46, I can't remember. One of the above model numbers is actually the 98 action, I believe, but I'm not sure which. Anyway, I can't tell you anything about the serial numbers, but these guns are very nice, smooth, strong, well made and accurate rifles. Swedish steel is among the strongest steel. And they are usually very reasonably priced. As far as ammo goes, I make it from 8x57 brass. Just run the 8x57 brass through the 9.3x57 full length sizing die, and presto, instant 9.3x57 brass. There are several web sites that have some reloading data for it. So, if you don't reload, finding ammo can be a problem. I think Normas still loads some, but it probably is not cheap.
If jpattersonnh would chime in here, I believe he can offer more info than I can.