The ukuleles made by Martin for the Oliver Ditson Co. Music Store in Boston are among the most collectible ukes out there. Here is a site with a comprehensive history of Ditson ukes. Link
Multi-instrumentalist and, like yours truly, a former Ringling Brothers and Barnum & Bailey Circus clown, Scott Linker has a new ukulele-infused album out. For me, this is kind of like Harpo Marx cutting a record: for all his years in greasepaint, Scott worked silent. It's lovely to hear his voice!