It’s been awhile since the original post was made, but I’d bet anything those four large pipes were the only ones that wouldn’t fit in that large pipe rack, without modification.
Those aren’t cheap pipes. They likely were birthday and Christmas gifts.
Somewhere, once upon a time in Grandma’s basement or attic, there were lots more of Grandpa’s pipes. They may still be there.
Grandpa likely didn’t buy that 12 hole walnut pipe rack and then modify the front six holes to fit only four large pipes. He even had two individual pipe stands. That man was a devoted pipe smoker.
There may be dozens more, someplace.
Happy hunting!