The duo arrived at Aldiss Park in January 2019 and signed new two-year deals with the club little over 12 months later.
The Magpies finished 10th in the Isthmian League North Division last season, before a reallocation of the leagues saw them moved to the Pitching In NPL Midlands Division ahead of the 2022/23 campaign.
The club have not disclosed the reasons for Gusterson and Willis’ departure but say further details will follow in due course.
A statement read: “We thank them both for all of their efforts whilst managing the club, namely driving the club away from relegation and winning the Senior Cup in their first season.
“We of course wish them all the best in the future.”
Photo Credit: Dereham Town
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