At the very least we should be able to "lock" items so they can't be dismantled without us manually unlocking them. However, I'd agree with the opening post & PepeSmug that we should gain the crafting recipe for all iconic weapons we get, especially if they're going to be parts of future crafting recipes.
The fact the current iconic description makes it sound like you'll be able to craft it again (or at least new versions of it) without saying "ONLY IF you keep this particular item" just makes it that much worse.