Checked my pictures and the only examples on a car, are restored cars
These pictures were represented as NOS examples - take that for what its worth. Don't recall shaker scoops NOS in the box having a seal installed.
Now that I've given it some thought there was a display at Perkin's shop at one point (could still be there) that had what was likely a white shaker that looked like the one in the pictures
IMHO if I were looking at other sites for research I would suggest the 428CJ site over Vintage.
OF course "facts" get mentioned one place - seen - then repeated over and over so got to be careful