Vintage Long Navajo Sterling Silver Ball Necklace with Graduated Bench Beads

A fine old long Navajo bead necklace made of sterling silver with graduated size.  The necklace is from the 1960s or 70s The hollow pearls are threaded on a silver chain which closes with a hook and eye mechanism.  In good vintage shape with no obvious dings to the beads.  Could do with a polish.

Marked "sterling"  under a rising sun motif on the end cones.  

• Length is 74 cm or 29 inches.
• The smallest bead is 4 mm across and the largest is about 15 mm across
• Weight is 41.7 grams.