There are 39 blocks, with features from the 1934-1935 sets as well as the 1937 sets. This may indicate a transitional set, an unidentified non-36-block set, or simply replacement blocks. The most significant anomaly is the use of the early-style (pre-1938) door and windows, which don't appear in the catalogs during the time the wagon was illustrated (1934-1935). They do appear in the 1937 catalog, but those sets do not include Byzantine Arches and Buttresses.
Blocks included: