Circa 1924 - 1930 - Early (left) and late (right) variations of the No. 331 Target Signal. Below is a  crossover example with a red base and white hood. In 1931 this was cataloged as a No. 1885 when it came with wide gauge track and a No. 1886 when it came with 0 gauge track. Below is the front/back of either a late 331 or 1885.

Circa 1931-32 is the 1885, physically identical to the 1929-30 version of the 331, just the catalog number and box were different.

Circa 1924-1930 - Early (above) and late (below) variations of the No. 332 Automatic Bell Signal. Note that the example below right has the Lionel bell mechanism on it and is probably from 1930 only. Variations from 1928-1929 would have the maroon base but the IVES bell mechanism similar to one above. We also have reports of a bell with with a painted white diamond base. Note the white painted sign above and the brass etched sign below.

Circa 1924-1930 - Early (above) and Late (below) variations of the No. 333 Banjo Signal. Note that the one above has a red light inside and the bell mechanism is also internal. The example below has a red disk in the opening and has the Lionel bell mechanism on the outside.  See pictures below for other variations.

The example above has the 1929-30 box, the one below has a box that would indicate 1927 or very early 1928. This could mean that Ives switched to these late colors in 1927 or that this is a very rare example from the early 1928 period.

Example on left (circa 1926) has red lens and bell mechanism inside. Example on right (circa 1929) has late colors with red lens and outside IVES bell mechanism.

Here's one that is a little different, wiring box read "PR" .. Pennsylvania Railroad?

Both the No.  332 and No. 333 came with Lionel bell mechanisms in 1930 (note the IVES lettering on the back of the mechanism box). The example on the right is either a late No. 332 or a 1863/1864 from 1931. The 1931 catalog showed the 1864 as above but the 1932 catalog showed the Lionel Bell warning signal as below. The No. 1884 below is identical to Lionels except it is rubber stamped with the IVES number on the bottom

An Ives 1908 signal - identical to a Lionel No. 78 except for the number on the box.