VAT rate of 5% is payable on hammer price and at 15% on the buyer's premium
The vendor recalls buying these slides at Sotheby's Belgravia in the 1970s or early 1980s.
Magic Lantern Slides
'The Three Dutch Conferences at Leyden' in Bulletin of the Scientific Instrument Society no. 43 (December 1994), pp. 10.
Encyclopedia of the Magic Lantern