The Yugo K98s were made in Germany or Czecholoslovakia originally and rearsenalled by the Yugoslavians. Mostly they are simply K98s that have had the receiver stamped with the Yugo crest and sometimes the waffennampts have been ground off or pinged out. They are of higher quality for the most part than anything the Yugoslavians ever made.
There are also some Russian rearsenalled K98s floating around out there, that have had the bolts blued and will almost always have mismatched bolts,but on the upside, the Russians knew how to use headspace guages.

If you are talking about the m48s, they are not K98s at all, but are more similar to FN-24s of which Yugoslavia made a clone of before the war and rearsenalled after the war. The M48s are a decent cheap rifle but they lack the fit and finish and overall quality that a pre war Mauser 98 has. There are also some well known issues with the M48 rifles such as rough locking lugs that make for difficult extraction, and out of spec or or poor quality bolt parts that can cause the safety to not work.