Has anyone ever seen an original solid left sidewall '98 Mauser rifle for sale? I was wondering how many were produced? Was the solid left sidewall made for cosmetics/safety/ or strength?? I was told that the thumb cut version bled off pressure better than one with solid wall, is that true? Is there any difference in an original solid left sidewall Mauser and a FN supreme 300 single C cut??

The thumb cut allowed gases to dissapate before reaching the shooter's face. It also allowed the shooter to easily clear a cartridge from the left side rail when loading without a stripper clip. Obviously, it is an aid in using stripper clips with your left hand, though most shooters use their right hand for loading.

Here is an article by Speed. It indicates how many original Mausers had a solid left wall.
Speed Article

Thank you for the article.