Make accurate plan of PM’s place (9)
I believe the answer is:
chartwell
'pm's place' is the definition.
(home of Winston Churchill)
'make accurate plan' is the wordplay.
I cannot quite understand how this works, but
'plan' could be 'chart' (chart can mean a plan or diagram) and 'chart' is found in the answer.
The remaining letters 'well' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'of' acts as a link.
Can you help me to learn more?
(Other definitions for chartwell that I've seen before include "Churchill's place?" , "Winston Churchill's Kent home" .)