I picked up a used JBL Competion Magnum XHD gun (4D45XHD) to use on the wrecks in NC and trashed the shaft on a fairly large grouper. I have searched JBL's website for shaft info and have found none. Leisure Pro still sells this model but the shaft length is listed at 48" while the shaft length for the same gun in "non XHD" format is 40. I lost the bottom half of the shaft and cant measure it. Any ideas what I should buy as a replacement and also where to look?