Cotter was a collector active in the later C20 based in the Dee estuary area of the UK.
His residual collection was sold to TVM in September 2022 via an intermediary, and comprised c1800 pieces.
As a field collector Cotter had particualy good local access to North Wales/North West UK localities, such as Halkyn, Great Orme which otherwise have become inaccessible in recent times.
Apart from the locality pieces the collection contains a wide range of UK and worldwide pieces acquired before the days of the Internet.