I recently used threaded inserts on a turntable project (see photos). Basically, figure out what size screw/bolt you want, then get the size of threaded insert to match the screw. Test on a piece of scrap first, make sure you're drilling the right sized hole. Again, the hardware store ought to have them. The detail photo shows one of them, albeit blurry.Loctite is a liquid that dries to rubber-like consistency, whenever you have metal-to-metal contact it helps prevent loosening due to vibration. The medium-strength stuff unscrews pretty easily, it's not permanent.
Best of luck with your project. I'll bet it will sound fantastic.