As a point of reference, I have a 100% refinished Crown Grade 12, regular frame with ejectors, very nicely restocked in original pattern but to modern dimensions. Two very knowledgeable double gun dealers told me a couple of years ago that it was at that time a $7500 gun. Yours is original pre-'13 with two sets of barrels, so I would start at $10K for insurance. Given the difficulty of finding another one like yours, $15K may not be out of line for coverage, depending upon the actual condition of the gun and its barrels. If you expect to collect in the event of a loss, you will want a professional appraisal on the gun to support the value.
You may want to call Walt Schiessl to discuss your gun.
http://www.doublegun.com/waltschiessl.html 714-956-2869
Puglisi recently had a couple of Crowns on the site and currently shows a 5E Damascus sold at $3950.
http://www.pugsguns.com/displayItem.do?id=956
