It's like post war Germany, for 30 years they could barely produce a cutlery set, then they got western support for their military-industry complex and became one of Europe's biggest arm's manufacturers in a decade.
What are you talking about? The "Bundeswehr" (German Army) wasn't created till ten years after WW 2 (1955) for political reasons, not technological ones. Germany started developing their own military equipment - like the Leopard 1 mbt - only one year later (1956) with mass production / delivery in 1965. The tanks were also sold to other allies shortly after that.
There was economic support in 1948 (Marshall-Plan) only three years after the war and some transfer of equipment when the Bundeswehr was created (1955), because western allies actually wanted West-Germany as a buffer for the UDSSR and development and production takes some time.
There wasn't any massive rebuilding effort or transfer of technology in 1975 and building up to date military equipment certainly wasn't a problem long before that point.