museum piece vs treasure

museum piece

noun
  • A very old item, especially an obsolete piece of technology. 

treasure

noun
  • A collection of valuable things; accumulated wealth; a stock of money, jewels, etc. 

  • A term of endearment. 

  • Anything greatly valued. 

verb
  • To store or stow in a safe place. 

  • To consider to be precious; to value highly. 

How often have the words museum piece and treasure occurred in a corpus of books? (source: Google Ngram Viewer )