@rive_gauche contact his gallery (Kendall kopppe) with a photo and dimensions and provenance, explaining you want a valuation for insurance, they should be more than happy to give you one (though I have a feeling kopppe of Kendall kopppe has left ship and opened a new gallery called kopppe astner so they might be worth a go too)
Good choice, no offence intended.
@rive_gauche contact his gallery (Kendall kopppe) with a photo and dimensions and provenance, explaining you want a valuation for insurance, they should be more than happy to give you one (though I have a feeling kopppe of Kendall kopppe has left ship and opened a new gallery called kopppe astner so they might be worth a go too)