Very first 1129 with two piece steam chest and NO BELL. The lack of a bell only on the very earliest.

Circa 1915-1916 - First series 1129. The easiest way to tell the difference is to look at the steam chests which have an indentation in the casting to make them appear as if they were two-piece (see below).

Circa 1916 - 1920 - Second series 1129 with one piece smooth steam chests.

No. 40 tender that came with all the 1129 locomotives, although note the differences in the tender below - lettering and the trucks. One above is middle period, below later and below that is the earliest version of the tender.

Note the unique bell found only on the 1129.

Under carraige of 1129 and it's tender.