High-class warehouse filled with new flip-flops (3-3)

'high-class warehouse filled with new flip-flops' is the definition.
I don't know anything about this answer so I cannot judge whether this works.

'high-class warehouse filled with new flip' is the wordplay.
'high-class warehouse' becomes 'depot' (I've seen this before. I am not sure about the 'high-class' bit.).
'filled with' indicates putting letters inside.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'flip' is a reversal indicator (the order is flipped over).
'depot' enclosing 'n' is 'dnepot'.
'dnepot' written backwards gives 'TOP-END'.

Can you help me to learn more?