The Caterpillar 594 Pipelayer in 1:50th scale was released by Gescha in 1973 with #2872.
If you are in the possession of photos or additional background information like brochures or specsheets about the 1:1 Caterpillar 594 Pipelayer I would be happy if you send your response to info@minimovers
I am particularly looking for the original English specsheet.