Pretty awesome question SkaerE.
Books have been written about Mauser bolt guns. The variations are mind boggling.
In brief, there are different models such as 71, 71/84, 88, 89, 90, 91, 92, 93, 94, 95, 96 and 98. In general, these models are different from each other. However, some are slight modifications of earlier models. The 98 is the last and best designed of these.
These models, esp. the 98, were built in different locations and at different times. Great variations in quality are encountered. The German 98’s (except late WWII production) are among the best, Chinese 98’s are probably the worst.
To make things even more confusing, sometimes a production run of 98’s have been given a totally different model number.
If you want some basic info, I’d suggest you get a copy of Frank de Haas’s “Bolt Action Rifles”, third edition. This book isn’t especially expensive, plus it covers a lot of other bolt guns.
The Yugo 98 rifles floating all over the place right now are good values for the price and would make a decent scout rifle.
Rebarreling a Mauser requires tools and gunsmithing skills. It’s not that hard but you certainly can’t do it on a kitchen table. Changing to a different cartridge can make things more complicated.