During his twenty years as a retired physician, David has turned his avocation as a self-taught scholar and collector of American antique clocks, watches, scientific instruments, and fine arts into an evolving multi-faceted vocation. In addition to operating Father & Son Antiques with his son, Ed, David has lectured, researched, and published numerous articles and book reviews, provided appraisal consultations for antique dealers, insurance companies, legal firms, and private individuals. David has also served as an expert witness for horological related cases and continues to appraise antique clocks, watches, and scientific instruments on a daily basis.

Notable achievements and associations include:

• Collector of Americana and American Clocks since 1966;
• Member of National Association of Watch and Clock Collectors (NAWCC) since 1967;
• Co-owner of Father & Son Antiques, Sussex and Morris Co, NJ, since 1993;
• Horological feature writer for The Maine Antiques Digest since 1995;
• Horological article writer for Bulletin of the National Association of Watch and Clock Collectors since 1996;
• Clock and watch appraiser for www.valuemystuff.com, London, GB, since 2011;
• Clock, watch, and scientific instrument consultant for www.stuffsavvy.com, Chicago, 2017;
• Clock and watch appraiser for www.lofty.com, New York, NY, 2013-2016;
• Lecturer at NJ Council for Humanities, Trenton, NJ, 2003-2015;
• Clock and watch appraiser for www.whatsitworthtoyou.com, Canada, 2006-2013;
• Curator of Clock Exhibit of Handmade New England Timepieces at Museum of Early Trades and Crafts, Madison, NJ, 2001.

Book reviews published in Main Antique Digest and NAWCC Bulletin:

• "Timeless: Masterpiece American Brass Dial Clocks" by Frank Hohmann III, 2009;
• "Harbor & Home: The Furniture & Clocks of Southeastern Massachusetts" by Brock Jobe, Jack O’Brien, and Gary Sullivan, 2009.

Research articles published in Main Antique Digest and NAWCC Bulletin:

• "Eli Porter, Clockmaker of Williamston, Ma.", 2016;
• "Leslie Fliegel Lost and Found: His Art Work Through the Lens of Time", 2014;
• "Who Made My Clock? Clue: He Worked with Rittenhouse", 2014;
• "The Hunterdon County Clock Case and the Enigmatic John Guild", 2013;
• "History of Clockmaking in Flemington, Hunterdon County, New Jersey, 1790-1840", 2012;
• "Will the Real John Adams Please Stand Up: Cabinetmaker John Adams, Chatham, N.J.", 2010;
• "The Johnson Clockmakers of Sanbornton, N.H.: Highly Regarded, Little Known", 2010;
• "The Matthews Egerton: Family and Furniture: What’s Attributable, What’s Not!", 2009;
• "A Willard Banjo clock, circa 1982: Something Old is New Again", 2009;
• "Reflections In Glass: The War of 1812-Uncovering the Print and Painting Sources for the Reverse Glass Naval Battles Found on Federal Clocks and Mirrors", 2009;
• "A Rare Lyre-Form banjo clock and the Life of Clockmaker Samuel Abbott", 2009;
• "Making a Case for the Transitional Case: New Jersey Tall Clock Cabinetry, c.1790", 2008;
• "The Easton Home: Antiques and Seniors under the Same Roof", 2007;
• "The Life and Work of John Scudder, Cabinetmaker of Westfield, N.J.", 2007;
• "A Unique Clock from a Unique Clockmaker, Jacob D. Custer, Norristown, Pa.", 2007;
• "New York City Gothic: The work of the DeMilt family of NYC clockmakers", 2006;
• "A Lantern Clock by Early Philadelphia Clockmaker Abel Cottey", 2006;
• "Great Treasure in a Small Museum, The Life and Work of Edward Duffield, Philadelphia", 2006;
• "The First Clockmaker of Elizabethtown, New Jersey: Aaron Miller ca. 1710-1779", 2005;
• "John Nicholl, Clockmaker of Belvidere, New Jersey: A recently discovered autobiography", 2005;
• "A Rare Berks County Banjo Clock Joins the Wood Front Lineup: Joseph Fix Reading,Pa", 2004;
• "Anthony Ward, New York City and Aaron Miller, Elizabethtown: Master and Apprentice", 2004;
• "Rare Reverse Eagle Painting on a Hoadley Shelf Clock: By glass painter William Fenn", 2004;
• "The Connecticut Dwarf Tall Clock- Or is it a Shelf Clock? C. Jerome & C. Boardman", 2003;
• "The Connecticut Wooden Works Banjo Clock: a late Terry product", 2003;
• "Daniel Porter, Williamstown, Ma.: An Apprentice to Daniel Burnap, East Windsor, Ct.", 1996;
• "David B. Warren, Merchant and Jeweler of Providence, R.I.", 1995.