Googling really doesn’t reveal anything at all about Alexis or Impextra Corp.

The movement is a Seiko 3302A although you’ll be hard pressed to see any identifying markings other than those of the retailer. It 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; there is a battery hatch on the back.

All have a crown between 2 and 3! They probably date from about 1973.