The most common and most likely answer to this crossword clue is the 10 letter word PROSTHETIC
I've seen this crossword clue in Independent
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More clues leading to the result PROSTHETIC
Buddy explains!

The straight part
We know that "about replacement parts" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case about replacement parts = prosthetic.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PROSTHETIC mean?
PROSTHETIC noun- An artificial replacement for part of the body; a prosthesis, prosthetic device.
- An addition to an actor etc.'s body as part of a costume, intended to transform the person's appearance.
- Artificial, acting as a substitute for part of the body; relating to prosthesis