Sinkinson, John H.
From Santa Cruz County history wiki
John H. Sinkinson (1847-1927) was a native of England who ran a wood-turning mill 1910-1925 on Potrero Street. The mill building formed the core of today's restored "Old Sash Mill" complex. Developers of the early-1970s restoration project were Lee and Marion Zeidler.
- John L. Chase, The Sidewalk Companion to Santa Cruz Architecture (4th ed. 2023), Chapter Six, item (2), page 183