Originally Posted by Philip
Rick, it may be that this batch that Turner bought in Belgium was assembled and then simply warehoused before they could be fully finished (note the grinder marks), and drilled and tapped for the sideplate screws needed to mount them onto whole guns. If they were made sometime between WW II and the 1950s, the market for such things in the final decades of the African colonies might have simply petered out due to the influx of inexpensive surplus rifles smuggled in from postwar Europe.
Long guns with this type of Portuguese lock were made in Belgium in the 19th cent. and possibly before. There is one of superb quality, maybe made in Liège and probably for export to Portugal or its colonies, dated 1821 that is published in Rainer Daehnhardt / Claude Gaier, Espingardaria Portuguesa, Armurerie Liègeoise (1975), pp 86-87. The specific type of lock is a fairly late one originating towards the end of the 17th cent. in Portugal, a Luso-French mechanical hybrid combining the innards of a French flintlock and the exterior design of the earlier Portuguese fecho de molinhas. The centuries-long presence of Portugal as a colonial master in equatorial and east Africa (Angola, Guinea-Bissau, Moçambique, etc) created a familiarity with and demand for Portuguese armament among the local cultures. (hence the local production of crude copies of 15th-16th cent. Portuguese and Spanish-style broadswords as symbolic regalia in Kongo and other areas down to the last century).