It's my understanding the collection is to be sold as a whole; not broken up as individual guns which is why it hasn't sold previously. I would bet they will eventually be broken up, perhaps into 2 or 3 gun sets.
20 years ago, there was a collection for sale of pre-1960 standard grade 21's that were unfired in their original boxes...they didn't last long.
As to why someone would have such a collection of custom ordered high grade guns and never fire them.....why the hell do people collect stamps they never lick and stick on an envelope?