Some notes to add from my research. Early 69s used the 68 style voltage regulator mount with rubber insulators, screws and ground wire. I think the screws mounting the regulator right to the core support started about Jan 69.
Also, C60 AC hole provisions were added at the beginning of the year according to my data. They were needed to mount the AC condersor on 69 models. If these holes were not there, how would you mount the condensor? Totally different AC system from the 68 model year.