Le Gant was a brand name of the large American department store, Montomery Ward.
The first set of photographs show the Seiko based Le Gants that I own. The movement runs at 21,600 BPH and is similar to the later Seiko EL-370. Access to theses movements is through the acrylic crystal; the stem is removed by pressing a small tab between the dial and case edge. In the three movement photograph below, you can see the gap in the movement ring at 4 oclock that allows access to this tab. There is a battery hatch on the back. They have a crown between 2 and 3 and probably date from about 1973.
This Le Gant World Timer uses one of the Swiss made Dynotron movements, the ESA 9154: