Mark,
I am a member at hempstead, and you are correct, the course was originally laid out by Lees and added to by Tillinghast. The club lists both as architects on the scorecard.
It is a fun course, and a great family club. The 3 par threes each have challenging greens and good distance variety. The three par 5's are also a nice mix. There is some repetition among the 12 par 4s, with heavy trees guarding the right side of many, and bunkers more off to the side than strategic. Thousands of trees make for pleasant viewing, but probably not what was originally intended. All in all, I enjoy all my rounds there. The course gets heavy play, but always at a nice pace, and easy to walk. A lot of nice traditions (including a 4 lane bowling alley in the basement) and friendly and enthusiastic membership - a model country club in many respects.