I can't read German so can't read the description. But that rifle might be a fantastic deal. What you must determine is if rechambering to 450NE 3 /14" will clean up the 458 Lott chamber. I know it will clean up a 458wm chamber. If it won't, then you need to determine if the rifle has enough steel in the barrels to stand rechambering to 450NE No2, which will almost surely clean up the Lott chamber.

While your at it, find out how much the rechambering, and possible reregulation will cost.

If the math all still works out, buy the rifle and try it as a 458wm or Lott (458wm ammo is safe to shoot in the Lott chamber.) You may find that its performance and its extraction and ejection are flawless as is, obviating the need to rechamber, or you may find issues and need to rechamber.

I bought my Marcel Thys sidelock in 458wm with every intention of rechambering to 450NE 3 1/4" and was pleasantly suprised to find it unecessary. Hundreds and hundreds of rounds, 18 elephants, four cape buffalo, one zebra, one klipspringer and a baboon mercy kiling later, all as a 458wm, and peformance and function remain perfect.

JPK