In the same way that some estate agents might refer to a small flat as being compact and bijou. Engineers selling old equipment on auction sites might use alternative phraseology to encourage sales of their old junk.
Unique design = None Standard / incompatible with anything else.
Needs attention = It’s broken
Easy to operate = I lost the manual
Missing Manuals = I broke it and hid the manuals
Ginger chrome = Rusty
Aged Patina = Rusty
Exhibition quality = Have painted over the rust.
thanks to the chaps at the Model Engineering Clearing House for some of these definitions.