Assuming the barrel’s good, you got a good deal on a shooter-grade 98. Enjoy it as-is after replacing the rear sight. The path to a nice sporter is fraught with peril for a novice, and expensive for anyone, not to mention the difficulty you may have finding a really good gunsmith. Better by far to pick up a nice commercial one like an FN, or someone else’s custom, at a fraction of the price of having one done yourself. Nice ones appear here in the classifieds all the time.
