The top was cleaned with a power wire brush and then finished with a quarter sheet sander. I fitted a new belt by unbolting the motor and then clamping it back down. I got the length right on the second attempt. A new switch has been fitted to replace the tiny unsuitable original one. Next job is to find a spanner to fit the blade nuts. 9mm is too small and 10mm is too big. I’ll raid the donated spanners at the shed and grind one to fit.