I bought these Märklin Sets recently on E-Bay with the intension of using the parts for model building. However, since the original mounting cards are in good condition, I decided to reconstruct them. A picture was available for the 101 set so that the layout is probably almost correct. The wheels are mounted on the original mounts which were fastened to the card base. Some of the clips securing the other parts have been replaced. Note that the aluminium flexible plates are painted blue on one side only - a feature often used on models. It is the Märklin development of the 1914 Meccano Set 1.  It is one of the first with 2 Universal Zahnrädern replacing 2 1” pulleys in the earlier version. A leaflet was included showing how they  could be used, but no models in the manual used them. I decided that a 14 tooth Zahnkranz für Tell Nr. 22 (a “pastry cutter)part 89/22 was missing. Marks on the mounting card suggested that it was stored under one of the large wheels. It is now under the Part 52 wth a hank of Cord and a Transmissions-Spirale