Watch List notes:

Commemorative Medals, Astronomy, Germany, Heinrich Wilhelm Matthias Olbers (1758 – 1840), Astronomer, silver medal, 1830, by Chr Pfeuffer for G Loos, on his 50th anniversary working in Bremen, draped bust left, rev. legend in 15 lines within a border of stars, 50.5mm, good very fine, though obverse with patchy tone
Olbers was elected a Fellow of the Royal Society in 1804.