I had made a post on social media about the job I was doing. The young guns, peers where I work, all spoke up about worn guides being the cause. Surprise! New seals, no more start up smoke! On to the next!!
BTW, the guides are fine. It helps to investigate and learn the history of what you're working. Internally, this motor looks low miles. It just old. That'll make any seal harden up and crack!