officially there were 3 different Models in the 1000 series:
-1000 3C (First series, no Oil-Cooler, drumbrakes front and rear); built from end of 1973 to early 1974 I think
-1000 3C/1 (or 1000/1): officially with Disk-Brakes front, drum rear, spoke wheels, first 4xx bikes without Oil-cooler. Built from 1974 - 1975 or 1976, not sure
-1000 3CL: alloy rims with disks all around, first models still with upright rear suspension. Built from 1976 to - with some slight and some major modifications - 1981. All MK2 engines had the 1200 frame, still marked as 3CL (headstock)
As it was "fashion" at that time to give bike heroic names, the JOTA, MIRAGE etc. where introduced. Basically first bikes with different equipment directly from the factory (like 4/C cams, higher pistons etc.). Later and/or in different countries (some due to emission regulations), there were the same model names used with bikes with standard equipped engines (like for Germany, I think there were officially no 4/C equipped bikes delivered. May be wrong though...)
HTH