Bidspirit auction | Dr Mart de Groot (Director

Dr Mart de Groot (Director of Armagh Observatory) Signed Bicentenary of Armagh Observatory Benham's Silk Cachet FDC With 4 British Stamps and One 16 Oct 90 Postmark. Est. Good condition. All autographs come with a Certificate of Authenticity. We combine postage on multiple winning lots and can ship worldwide. UK postage from £5.99, EU from £7.99, Rest of World from £9.99