This double bass is a Kay M-1 from 1949, serial# 19114. I bought it in 2011 and used it for bluegrass, acoustic rock, and Americana. In 2017, Gael McKeon in Berkeley did some significant work on the fingerboard and bridge, matching their radii. Recently, Nathaniel Rich in the same studio eliminated a buzz by trimming and gluing some delaminating wood in the interior. The bass has the original Kay tailpiece, and a replacement endpin (less rattly than the original).