Here is a link to a post describing the history of the AMT Corporation, the famous manufacturer of dealer promo models and plastic kits, that mentions an assembled toy/model with a clockwork motor:
http://www.motorcities.org/Story/Rememb ... n-348.html
The first image in the post shows a circa 1951 flyer for the Henney model. From the article, "In 1951, AMT produced an authentic model of a Henney-Packard ambulance in 1/20th scale. This model was not very popular among the young kids at the time and through 1954, AMT continued to struggle within the sales markets."
1/20 scale Henney-Packard ambulance model from 1951
Re: 1/20 scale Henney-Packard ambulance model from 1951
Be nice to find one of those "not very popular" $3.98 Henney models today. I'd bet it would go for about as much as a downpayment on the real thing would be.