Oh well
I ordered the mainsheet system by phone, knowing what I was buying (a replacement). The sheet (endless splice) was quite twisted in the mainsheet system and kinked. This could be corrected reasonably well.
I wanted to buy a matching premium snap shackle for the system.
Unfortunately, despite explicitly asking, the bolt of the WICHARD snap shackle didn't fit through the hole in the block – the only reason I contacted them by phone.
The goods arrived two weeks later than expected, too late for my vacation – without any prior notification.
Overall, I'm left with a bad feeling.
The customer service was friendly.