Vintage 1960s Fred Roberts Bird Irish Coffee Mugs, Set of 4

This is a set of 4 vintage Fred Roberts Irish Coffee Mugs that are great vintage condition and absolutely adorable.
No chips, cracks or fading.  There is a slight stain in one of the mugs (see picture)

They are vintage porcelain, each foot is a different color & song bird hence the name of the collection "Song Bird"
The colors are vibrant and stunning in person, a true reflection of the MCM design that we just adore!
Height: 5 1/2"
Dia: 3" at mouth 4 1/2 with handle
Capacity: 8 oz.