Generally agree, but I think that by 1880 the British had finally come to their senses and given up on Arctic exploration. Franklin's expedition [0] was 1845 - 1848 or so, and the subsequent extensive searches for him into the 1850s provided a lot more knowledge of the geography, but they seem to have also made everyone finally confront the futility of the task. The British Admiralty didn't fund another expedition until 1875-1876 when the Nares expedition to reach the North Pole failed [1], and the general conclusion was that there was no Open Polar Sea. They gave up on Arctic exploration after that.

So maybe shift 1880 back to 1840.

[0] https://en.wikipedia.org/wiki/Franklin%27s_lost_expedition

[1] https://en.wikipedia.org/wiki/British_Arctic_Expedition

EDIT: formatting