Congrats on getting it together.
Don’t know a heck of a lot about military 98s, only that there’s a heck of a lot to know and I’m mainly interested in hunting rifles, but that paint might be original like No.4 SMLEs or arsenal rework. No matter for range work anyway. All the finish options now are frightfully expensive except DIY.
As for the sights, cast loads may shoot higher due to longer barrel time, but only one way to find out. I have a similar issue with a commercial FN and the oddball dovetail means I’ll have to do some extensive file work on a replacement blade, which most likely will be a brass one from Skinner. BTDT with others. Meanwhile, I have a Weaver base on the receiver ring and a 2moa red dot, a good hunting combination. This one, like some others I’ve owned, was drilled for some unknown bases from the past, so trouble-free scope mounting is out. The stock is shaped for irons anyway, so I’ll put the sight issue on the Someday List and shoot it as-is for a while. I was fortunate in finding a pristine Lyman 57FN at a very good price and managed to fit it with minimal blood loss.
FWIW, if you decide to shoot some jacketed loads, I’ve gotten excellent results in about a half-dozen ‘06s with 46gr of H4895 and 150gr bullets. Should be close to military ballistics, and is mild and accurate.