While he was more famous for his overall Star Wars costume design work, including winning an Oscar in 1978, John Mollo has been mentioned in the overall history of Boba Fett.
Specifically, he worked on the soft parts of the white "supertrooper" costume which led to Boba Fett. This is confirmed in "Star Wars Costumes" (2014) and was also brought up on Joe Johnston's social media page once. Do a quick Google search and you won't find any results on this -- besides BFFC. ;-)
"'Norman Reynolds called me in to do the actual costume of the bounty hunter between the two Star Wars films,' Mollo says. 'We met and he showed me the model of the helmet they were making, and I went about getting the suit made.' ... Mollo drew up the soft layers of the costume, including the jumpsuit and the vest the armor would attach to, and had them created at Bermans." -- Excerpt from "Star Wars Costumes" (2014) by Brandon Alinger
Obituary: http://www.hollywoodreporter.com/news/john-mollo-star-wars-costume-designer-dies-at-86-1052713