France, May 23 -- Theirs was one of the hundreds of Parisian families who moved to their country houses during the Covid-19 confinement in France. But unlike most others, this rather dull period has literally been worth its weight in gold for this family who made a very fortunate discovery.

Wanting to build a tent in their garden, the children in the family were looking for old sheets in their great-grandmother's cupboard when two small but relatively heavy objects tumbled on the floor.

The father, after being shown the grayish looking, dust-covered objects, recognised them as knife holders that his grandmother had used during family dinners for many years.

However, when his children mentioned the presence of serial numbers and inscrip...