April 1973 and November 1973 dates: Lewis, p. 141. This page at Cameraquest mentions a third version called "Minolta CL", sold in Japan and in the US after the Leica CL ceased to be sold. However no picture has yet been observed, and its existence seems dubious. It is also mentioned in this page at Pascal's Leica Pages, but the source is probably Cameraquest.
65,000 serial numbers: see this page at Cameraquest. The same page mentions 20,000 examples of the Leitz Minolta CL, but it is apparently only a guess.
April 1973 and November 1973 dates: Lewis, p. 141. This page at Cameraquest mentions a third version called "Minolta CL", sold in Japan and in the US after the Leica CL ceased to be sold. However no picture has yet been observed, and its existence seems dubious. It is also mentioned in this page at Pascal's Leica Pages, but the source is probably Cameraquest.