Unknown Model #6512

This is a mid-1950's model #6512 mandolin, which was Carvin's first foray into 8-stringed instruments.  It was offered in electric and non-electric versions, and this particular one is loaded with an  Alnico V pickup with volume and tone controls.  In 1955, this model sold for $59.90.

Unknown #3-MB

Here's a Model #3-MB, from 1968 in sunburst finish.  These mandolins were made from 'hardwood" with a maple neck, and were equipped with an AP-4 pickup, single volume and single tone controls.  They were also offered in natural blond finish.