set of 3 vintage Hartstone green checker mugs

Set of three vintage Hartstone Pottery ceramic mugs. I think these are from 1982, made in USA. Ivory with hand-painted green checker design along rim. Heavy duty, 16 oz mugs in lovely condition overall. There’s some minor scuffing to the bases (two of the mugs have small red marks also on base—see pics), and one mug has a bit of green glaze transfer near the handle (a maker defect, looks like), but no chips, cracks, staining, or crazing.