Question About A Few 1976 Coins

The S would be regular proof set, 40% would come from the 3 piece proof sets and 3 piece uncirculated sets

Just so I'm understanding because this is confusing to me.

The 40% S-Proof comes from the 3 piece silver set where the coins are arranged in the display case like a triangle? LIke this https://www.ebay.com/itm/313670165524 This is the set I bought (not this exact one obviously) and man was it hard to get the quarter out of the plastic unscathed.

The 40% S-BU would come in a set where they arranged in a line. Like this? https://www.ebay.com/itm/255132702327

Fabulous! Thanks. Still learning over here.

I had a discussion with the wife and son last night about whether I should buy two silver proof sets for each year. One to keep and one to break up into albums. The vote was buy one and put it in albums. My son kept asking "why do you want two?" I said one to have a display case that shows all the coins for a certain year and one to fill the album of each coin type. I lost that discussion, I wanted to buy two but since I'm playing catch up it's cost prohibitive.