The author of 'April Showers', the (then) new room in 'Jet Set Willy', published as a type-in in 'Your Spectrum' magazine in April 1985, is apparently John Nicholls, not Nichols. His surname is spelled with a double 'l' in the original article (page 41) where it appears three times.
I have always seen it spelled with one 'l' on JSW-related websites. This incorrect spelling is also present on WoS.
I imagine the error was perpetuated by people copying the surname from sources where it appeared earlier, without consulting the original article. I am sorry to admit I contributed to it, too, including in the text files which accompany 'Jet Set Willy: The 2010 Megamix' and its earlier incarnation 'Jet Set Willy: The 2005 Megamix', where Dave is credited because the room 'April Showers' is included in these games.
So, thank you for 'April Showers', Dave Nicholls, and sorry for misspelling your name over the years!
Edited by jetsetdanny, 24 February 2018 - 11:11 AM.