Last December I picked up a '94 Custom 24 Stoptail in Whale Blue that I love, but I'm continuing to have tuning issues. I've tried different nut lubrications but the issues persists. I tried doing a search of the forum but most nut replacements are done are SE models and not Core guitars. I'm looking to get a Black Tusq XL nut but looking on their website there are 50 different nuts. Any help with which one I should get specifically would be very helpful. Because I've never replaced a nut before and don't want to damage my guitar I'll be having a local tech install it for me.