Thanks for taking the time to outline the history of that particular cross.
I have many seedling x seedling hybrids here now. While I can trace back quite a bit in my head, there are also blank patches where I'm wondering "Where did that come from?" because my earliest records were lost several years ago and then labels where mixed up in moving too many times. I wish I could outline breeding in as much clarity as you do. Very impressive system.
Seed sowing is a fantastic time. Enjoy