Spanish Mausers have a mixed reputation in part because Spain used them so long--thus you get 1893, 1895 models which were originally 7mm small ring Mausers which is a weaker action than the M98 , and the later M98 large ring 8mm M43 models which is the stronger action. Some were rode hard and put up wet, some were repurposed, while others remained relatively pristine. Thus, like Turkish Mausers, some models are preferred by the Mauser aficionados more than others. Some of the inhabitants in the Mauser forums at collectors places such as Gunboards, milsurps.com, or other Mauser collector forums can probably give you very detailed information
If you want it as a collectible then get it. Probably not economical to sporterize it because you will lose the collectible value and have to spend more dollars to get the sporter you want. WWII era Mausers in their military trim in general are rising in price particularly previously less collected variants such as Yugo's, Czech's, etc. Even the lowly Turks have doubled their price in the past ten years just like the Mosins.
If you are worried about it, see if the seller backs their merchandise with a money back guarantee if a gunsmith finds problems after the sale so that you can return it if it is not safe. A good gunsmith should be able to determine if the rifle is safe to fire for relatively little cost--if you later sell it, you can also tell the buyer that you had a gunsmith check it out and provide proof that one did. You will also have a little peace of mind yourself. Good luck on your search.
