the basic idea is awesome. the parts with the known to build in is possible without any problems, I would even say that these stones are dimensionally better than the original, the part not all fit so perfectly if they originate from different production locations. For my son, it is currently exciting to watch the ball rolling, but he destroyed my work occasionally, but through creative play also can be recreated again. A tip to all mothers - you buy it when the fathers shall be busy times for a few hours.
