Otto Maier Verlag - rare graphic double-sided jigsaw puzzle for Ravensburger 1973

Very rare puzzle in original box. This is an early edition puzzle from the 1970s with a vibrant, colourful geometric design. It is double sided though we have only enjoyed completing the easier full colour side (Kuladot takes time to complete all jigsaw puzzles before listing so there are no disappointments). 600 pieces. Size when finished is 48.5cm x 48.5cm.Very satisfying locking of pieces - we were able to flip it to photograph the other side without it falling apart! In vintage used condition with expected signs of age such as box tattiness and the odd little crease on a piece or two but no missing pieces!
This is sold as a collector's item as it does not have current toy safety legislation marks. Small pieces could be a choking hazard for young children.