I'm not sure what this is supposed to show. Marx being famous for his critiques of political economy is not the same as Marx famously using the term political economy in a certain way.
Political economy as an area of inquiry took off in the late 18th century--in no small part due to Adam Smith--and was already very well established before Marx was born [1]. Absent evidence to the contrary it seems questionable to assert that Marx's use of the term was anything other than the common use of the time.
Political economy as an area of inquiry took off in the late 18th century--in no small part due to Adam Smith--and was already very well established before Marx was born [1]. Absent evidence to the contrary it seems questionable to assert that Marx's use of the term was anything other than the common use of the time.
[1] https://books.google.com/ngrams/graph?content=political+econ...