Found some additional information so hopefully this is the best - most correct - listing:
K-515701 - K-Line Loves California Boxcar
K-515702 - K-line Loves Colorado Boxcar
K-515703 - K-Line Loves Delaware Boxcar
K-515704 - K-Line Loves Florida Boxcar
K-515705 - K-Line Loves Illinois Boxcar
K-515706 - K-Line Loves Indiana Boxcar
K-515707 - K-Line Loves Maryland Boxcar
K-515708 - K-Line Loves New England Boxcar
K-515709 - K-Line Loves New York State Boxcar
K-515710 - K-Line Loves Pennsylvania Boxcar
K-515711 - K-Line Loves Minnesota Boxcar
K-515712 - K-Line Loves New Jersey Boxcar
K-515713 - K-Line Loves Texas Boxcar (added Apr 28)
K-515802 - K Line Loves America Boxcar
K641-740801 - K-Line Loves Chicago Boxcar
K641-740802 - K-Line Loves New York City Boxcar
K641-740803 - K-Line Loves Philadelphia Boxcar
K641-740804 - K-Line Loves North Carolina Boxcar
K641-740805 - K-Line Loves Los Angeles Boxcar
K641-740806 - K-Line Loves Ohio Boxcar
K641-740807 - K-Line Loves Virginia Boxcar
Originally I thought what appeared to be a random numbering scheme so kept checking. Now the above numbering seems to make a lot more sense.
