Did that special clip eliminate the staples?
"Eliminate" ? San Jose choose to use the clips rather than deal with the stapler for 68 and 70. As we've seen at Dearborn the stapler has issues at times forcing that workers to switch to a different style of clips when the machine was down. Guess San Jose just too the easy way. Might have been quicker also especially if they installed the clips on the seal before hand
My car still has broken remnants of the staples remaining. My car is a San Jose Sept. built.
Is/was your car an unrestored car when you got it? For decades (especially on San Jose cars that made their way east) restorers and owners added staples since it was believed in those areas that "all 69's were stapled" altering the original design and leaving details as you have found them. This seems to be more common on CJ cars so when you check these against 6 cylinders built about the same time the conflict and likely addition stands out.
Just mentioning a possibility - as I do have San Jose 69's that have staples added I believe in my picture files but what gets interesting and suggest they were added.
Earliest car I have with seal but no signs of staple use would be in the 9R106xxx range