On 1961 (with H4 letter code), the design of the end caps changes, acquiring some improvements on the design:
1.- End caps become one single piece. Until now the end caps were a continuity of the center bar, obtained bending the final part of the center bar and they were covered with a welded slim metal plate, that use to get lost. The end cap piece has a claw to fix itself to the center bar. It is set or crimped like jewels.
2.- Obviously, the final part of the center bar needs some changes too, to allow the end cap claw to fix. So it developes a dovetail termination.
This change was made during last quarter of 1961 (H4) so models of H4 code can be found with both types of end caps. But surely H3 models will have end cap metal plate, and I1 models will have crimped end cap piece separated from the center bar. |