Where can I look for the gear cornelis vreeswijk uses?

Find and submit the microphones, and other instruments used by cornelis vreeswijk.

If the artist is active on social media, check places like their Instagram feed and look for musical equipment they can be seen using.

You should also do a Google image search for things like "cornelis vreeswijk studio" and "cornelis vreeswijk live" and spot gear that way.