Despite the low number of rounds in Mausers, any classic 'Battle Rifle' is in much more demand-as you must know-when left in the original condition. Their value really drops. I would never look twice at a modified/sporterized type, no matter how low the price.
If you want ten rounds, you might want to consider handling a nice Lee Enfield #4 (maybe the #5) etc.
Those mags should be left in the rifles, as the feed lips can get bent from too many insertions. Cheap surplus ammo is very difficult to find in .303, but reloading works.
Have you handled them or watched them 'in action' on the better Youtube videos?