Great Dave,
But to get the look I wanted, I had to build the wall three times. Experiment & learn. The blocks are made from a type of linoleum flooring material that Bill slices up and scores the ends so they break with a realistic face texture. My biggest problem was the inconsistency of the block heights from the different batches he gets. The variances in width should also be taken into account. I believe they fit the best in applications where the 15" N scale height and 30" to 40" width are to scale.
Building a wall is easy with thick CA. Dot of glue, block, repeat ... Keeping the wall face vertical is the challenge in modeling. I ended up building the abutment with the face against the table to keep it in plane. Thick CA made that happen as thin would have bonded the entire wall to the table. As stated, after 4-5 rows, I sanded the block tops to keep the courses level. 60 grit and a flat surface did the trick. Very easy to sand. Trimming the blocks was done with rail nippers. Cutting a new face was done with a dull xacto blade and the block being cut elevated off the table surface. The material sheared in the same way as Bill's cutter does the original "face".