I have a 4.71m QHMC. It is a "put together." I have a type III trigger housing in it. Riesch says at SN 4.5m type III and Type IV saw mixed use. Ruth says type IVs came into use in Spring '44. Mine is a March/April '44 production date. Does anyone know the latest SN for QHMC that had a confirmed type III trigger housing? Thanks.