This series started at a wrong time, it went entirely against the spirit of the 60s, says John Banville in his introduction to vol 4 of the Parker series. You can say that again. Parker cares nothing about politics or wars or love, but he will rob you and kill you if you are in the way.
He cares nothing about art or history, but here he gets involved in art theft. Business is business. Parker works for money. If there is a history behind an art object, what does he care. The statuette in question, the mourning monk, hails from Dijon. Various historical events moved it to Canada, then Atlanta, then Boston, now Washington D.C. in the embassy of a fictional iron curtain country --- another intricacy that Parkers cares nothing about. Parker's patience is heavily tested by this tale. He likes his briefs to be brief.
The fact that the University of Chicago Press reprints the Parker series, and that they get highbrow Banville to write an introduction, proves at least, if nothing else, that the author Westlake/Stark has found influential supporters. It doesn't prove the high value of the writing. For that you need to see for yourself.
I have myself nearly quit the habit of reading crime series, but there are always exceptions.