I'm sure I'm not the first to do this, but here's an idea for reusing those old SO-239-style antenna mounting studs. If the main body of the SO239 section is in decent shape, use a punch/vice or other method to drive out the "guts". Locate a retainer nut from an old CB or HAM radio's SO239 fitting along with appropriate washer(s), and you have a ready-made bulkhead feed-through for some pretty big cable. Or a bundle of cables for that matter.
Remember, a true DIY-er never throws anything away, because "you never know".
Remember, a true DIY-er never throws anything away, because "you never know".