Later I ordered yet still another shell because I was disturbed the imprecise seat. This second shell would sit perfectly. Out of interest then researched and found that the variants differ in the housing 3 of Ace slightly:
S7270 (3G) and S7272 (3G + Dual Sim) with a case height of 9.8mm
S7275R (LTE) with a case height of 10mm
I was even überrrascht and so it would not surprise me if they are matched to the seller no one has thought about that Ace 3 Ace 3 just is not the same. If I were the owner of a 3 Ace S7270, so would use this product safely and properly, it would have given a positive review, because except the fit is all ok.
Would have been easy to avoid if the product description would take this into account.