My first kit (purchased in late 1972, maybe early '73) was the long box and the kit itself had the "loop" and "peg" approach to attach the nacelles. The light kit had been phased out by the time of this release. I didn't paint anything other than the engine domes and the main "dish", and like so many other kids, I used Testors red. I may have painted the back part of that dome piece black because the box art suggested it was dark.
About a year or two later I bought a second kit. It was still in the long box, but AMT changed the nacelle attachment method. A semi-circular piece aligned with the holes where the pylons fitted. Both the semi-circle piece and the pylon "tabs" had slots that fit each other at 90 degree angles. This provided a bit more stability. Ironically, that semi-circular piece was positioned more or less where the bulkhead of the shuttle bay would in the "real" ship. So I didn't glue the clamshell doors. Instead, I drew the deck detail of the shuttle bay (based upon the Franz Joseph plans) onto card stock and glued the trimmed paper to the model.
The previous kit? I lit a match and strategically torched sections, turning it into the wrecked Constellation.