| 1928 JOSEPH Railway Crossing Signal System Art |
| 1928 FRANK Rail Crossing Signal Patent Print Art |
| 1928 HERMANN Automatic Block Signal System Art |
| 1928 VALLEE Block Signal System Railroads Art |
| 1928 MARVIN Signal Indicator Motor Vehicles Art |
| 1928 FRANCIS Signal Art Print |
| 1928 ARMSPEAR MFG COMPANY Train Signal Lamp Art |
| 1928 ADLAKE CO Signal Lantern Patent Print Art |
| 1928 UNION SWITCH SIGNAL CO Electrical Art |
| 1928 SIGNAL GMBH Submarine Direction Finder Art |
| 1928 STEVENS JOHN Signal Patent Print Art |
| 1928 UNION SWITCH SIGNAL CO Decoding Art Print |
| 1928 WESTINGHOUSE AIR BRAKE CO Signal Art Print |
| 1928 WILLIAM Signal Art Print Patent |
| 1928 EWALD C DIECKERHOFF Signal Patent Print Art |
| 1928 GEN Block Signal System Railroads Art Print |
| 1928 WENHOLZ Block Signal System Railroads Art |
| 1928 HANS WERDER Signal EWALD C DIECKERHOFF Art |
| 1928 HENRY Block Signal System For Railroads Art |
| 1928 FRANCIS HOGG Signal Device Patent Print Art |