I recently played Trenton CC for the first time, and agree with the sentiments that the course plays significantly longer than its scorecard yardage. In addition to some genuine brutes (most notably the uphill par 3 3rd, par 4 4th, and par 4 11th), some of the shorter holes have pretty tight corridors (e.g. the 315 yard par 4 6th) that call for precision more than distance. For a player of my skill level, it presents more than adequate challenge, as even the holes that would seem to give an opportunity to score (short par 5 7th and 9th especially) are quite tough, due mainly to severe slopes on and around the greens. Like many shorter courses, the greens were the primary defense, and were generally quite good, with a variety of internal contour and slope in play. I'd also agree that TCC is a cool place, and a fun course. It has numerous "half-par" holes, and lots of unique features (e.g. driving over the 15th green from the 16th tee) that seem to occur on courses of its vintage (1898 & 1914).
During my round, our host (a very strong player and student of golf history and architecture) pointed out certain features that he attributed to Tillinghast. I have found a handful of references (listed below) to Tillinghast at Trenton, but none with much detail as to what work he actually performed there.
1. Tyler Rae's website lists architects J. Norton (1916) and AW Tillinghast (1934) in the section on his 2018 restoration work.
2. Pete Trenham's piece on the Milne family (professionals at TCC from 1941-2006) states that Alexander M. Milne (father of George, grandfather of Dennis) designed greens for Tillinghast, but does not specifically mention work at TCC.
https://www.golfclubatlas.com/forum/index.php/topic,56603.msg1314872.html#msg1314872"At one point Milne designed greens for A.W. Tillinghast. Tillinghast would describe what he wanted and Milne would create a mold of the green out of clay. The shapers would then use the mold to build the green."
3. Trenton CC's website lists Tillinghast a a "contributor to its golf program."
https://www.trentoncc.com/Amenities/Golf"Since its inception, Trenton Country Club has had several esteemed contributors to its golf program - Tillinghast, Calloway, our professional Emeritus George Milne and his son Dennis Milne who championed our junior program."
4. The NJ State Golf Association lists Trenton as a course where Tillinghast performed a "consulting examination," which is listed separately from original designs and reconstruction projects.
https://www.njsga.org/hall-of-fame/albert-warren-tillinghast-1876-19425. Phil Young's book on Tillinghast does not list Trenton CC in the "Tilly's Courses" section, or in the timeline of his PGA tours during the mid to late 1930s.
6. The Tillinghast Association website has far less detail than it once did, so that no longer seems to be a resource.
http://tillinghast.net/The old articles shared by Mike Cirba make clear that Jimmy Norton laid out the course in 1913-1914 (possibly including some holes from the original 1898 nine hole course), but there does not seem to be anything concrete on Tillinghast's involvement. I'd love to learn more, if anyone can share additional resources.