Marx Tin-litho Wind-up Sparkling Tank retailer (very rare)

Product Name: Marx Tin-litho Wind-up Sparkling Tank retailer (very rare)
This wind-up tin-litho toy features a sparkling mechanism and my particular sample runs like a spooked cat, sparkling all the way. This version of the tank features an unadorned turret dome and is a retailer bit more common. A harder to find - and more expensive - version of this tank features crew members lithographed on the dome. The windup mechanism seen in the photos was in common use by Marx I believe well into the '50s and larger versions of it were used on planes and vehicles. The key does not come off (a really good feature for people prone to losing things like that) and measures 5 3/8" (13.65cm) L x 2 1/4" (hull width only, not including key) (5.71cm) W x 2 1/4" (5.71cm) H.