
Sunset note dates from 1879/1880.
It is catalogued in MacDonald 1995 (cat. rais.) [more] (cat. no. 747). The entry has been revised.

Sunset note whereabouts unknown

Venice at Sunset, Portland Museum of Art

Sunset; red and gold - The Gondolier, Fogg Art Museum
It is possible this was a pastel of Venice, but there is absolutely no proof of this.
The size is indicated in the 1904 Boston catalogue and memorandum in Boston Public Library. It suggests a vertical composition but this might be misleading.

Venice at Sunset, Portland Museum of Art

Sunset; red and gold - The Gondolier, Fogg Art Museum
Possible candidates if it was in horizontal format would be Venice at Sunset m0741 and Sunset; red and gold - The Gondolier m0806
The drawing has not been located.