 Caledonia Mining Corp PLC has agreed to buy the Bilboes gold project in Zimbabwe in a transformational deal that it said could lead to a four-fold increase in the companys overall production. Caledonia has agreed to buy Bilboes Gold Ltd, owner of the project, for about US53.3mln 44.4mln in shares and a 1 net smelter royalty NSR on the projects revenues. 