Perhaps you could do a comparative shot with other Playmobil buckets for us.
The "usual mark" is just a mold mark, and would be used by many different manufacturers, so that doesn't help pin it down.
I've never seen a chromed bucket from Playmobil, and they have only a few basic styles in use. A bucket is, after all, a very old tool and the basic design is much the same now as it was in Roman times.