i have a great old leather jacket ive worn for years since new,the main zip is a bit dodgy gotta be sure its bottomed out before i zip it up otherwise the bottom comes out mid ride and unzips itself from the bottom up and is a #$%* to make right wearing it,i tried for weeks to find a place to replace the zip to no avail too heavy duty?the one place that can do it only use a new nylon zipper,#$%* that its gotta be a stainless steel or brass bloody zipper on an old leather jacket?