Sounds like a high-end rod. Online rod blank providers stopped buying Loomis blanks almost 20 years ago, when Loomis stopped selling them. They're all stocked out by now.
You can try Jann's, Flyrodcrafters, hookhack, and others. I know that Jann's and hookhack will quickly answer questions if you call or email. See if they sell a blank that comes close to matching the dimensions and action of your original rod. If in stock, there are a few lower end blanks for <$100 onto which you can transfer guides. It probably won't be an exact match, but you'll be able to show off a custom Frankenstein rod.