I just purchased an excalibur on eBay. It like new and appears to be in excellent condition, but I notice that the coil cover is fairly loose and I'm afraid that it might fall off from wave action when detecting in the surf. Is this normal for the cover to be so loose, and if not, is there an acceptable way to "tighten" it? Also, I promptly stripped the plastic bolt when I tightened the coil wing nut (I hardly put much pressure on it at all!). If it happened to me, I'm sure it happened to others! Must you go to a dealer to purchase these plastic bolts, or can they be purchased, at perhaps a hardware store? Any input will be greatly appreciated! Thank you! ~Larry~