LONDON.- What do one of Churchill’s cigars, a 35 million years old fossilised giant pig, a silver wheelbarrow presented to W.E. Gladstone, historic butterfly cabinets from the Natural History Museum and Christmas presents from the Duke and Duchess of Windsor have in common? They all feature in Bonhams annual Gentleman’s Library Sale on 19 January. During the war, portraits of Churchill were important propaganda tools but he rarely actually sat for them. In 1944 he did so, briefly, for the artist Frank O Salisbury who had already painted him many times. When the Prime Minister left, he discarded his half smoked cigar which the painter kept as a souvenir. It has been in the family ever since and is estimated at between £600 and £1,000. A perfect place to keep it would be one of the 46 collectors’ cabinets from the Natural History Museum. Until recently they hel