The spare parts replacement used the pins, and at some stage the production also switches to them. I have a Bulletin update for revision of the shaker seal with dates etc, but can't recall if switch from glued to pins or an alteration with the pin type, think I have both. Of course, if your shaker base has no holes, you know the factory, or previous owner, or warranty guys didn't drill it. Originality aside, the pins were probably neater and quicker to do, and use within minutes, yet took them years to think of!