Is there any way to re-obtain deleted achievement items?

A few months ago, I finally made my first purchase in TF2 and my backpack expanded accordingly. However, during my years as a F2P, I accumulated a large number of achievement items. Since I only had fifty slots and I cared most about having good weapons, I ended up deleting many achievement items (and the vast majority of random drops).

I've since found/traded for the few achievement weapons that I deleted, but I'm still missing three key items that I deleted and I'd like to have back: The Ghostly Gibus, Pyrovision Goggles, and the Headless Horseless Horseman's Haunted Scrap Metal, all of which I earned by getting the corresponding achievements. There's no way to earn an achievement twice (AFAIK), and these items are tied to the achievements themselves. So, is my Gibus forever lost, or is there some way I can find it again?

In regards to your title, since all achievement items are server based, you cannot get achievement items back once you get rid of them.

However, the items you have listed that you want to get back can be easily obtained. Here's how:

• The Ghastly Ghibus can still be traded for

  • There are 4 ghibuses, one that is a robotic version
  • If you want the look of the ghostly ghibus solely, you can opt to get the Ghastlier and Ghastlierest Ghibus and change the style. If you're aiming for the actual Ghastly Ghibus, there is no way to get it.
    • Ghostly Ghibus (has only 1 style, ghostly)
    • Ghastlier Ghibus (has 2 styles, ghastlier and ghostly)
    • Ghastlierest Ghibus (has 3 styles, ghastlierest, ghostly, and ghostly)
      • This is the most cost effective option
      • It's cheap and can change styles to the 2 older hats
    • Galvanized Ghibus (no styles)

• Unique (yellow) quality Pyrovision Goggles can be traded for

  • but are more expensive than a Vintage (blue) quality Pyrovision Goggles

• The Headless Horseless Horseman's Haunted Scrap Metal can also be traded for. Users can giftwrap it and send it to you, so you can trade for it. There also exists clean (tradable) Haunted Scrap Metal that can be traded without gift wrap.

So here's my advice for you:

• Do you have no money?
  • Get a Ghastlierest Ghibus. It is the most cost effective option
    • You can switch styles to that of Ghastly, to Ghastlier, or to Ghastliest, without the need to buy 3 seperate hats
  • Get a Vintage Pyrovision Goggles.
    • You can pretty much afford one from selling just 1 - 3 trading cards.
  • Don't get Haunted Metal Scrap, instead, try to opt for the Headtaker that is untradable
    • Prices are rather expensive in this case
    • Even getting the hat (Spine-Cooling Skull) and weapon (HHHH's Headtaker) are also relatively expensive in this case.
      • The Headtaker can be upwards of 1 ref (+ $1.99 USD Giftwrap) for untradable, 3 keys for tradables.

The other option:

• Do you have money?
  • Get a Ghastlierest Ghibus. It is still the most cost effective option
    • You can switch styles to that of Ghastly, to Ghastlier, or to Ghastliest, without the need to buy 3 seperate hats
  • Get a Vintage Pyrovision Goggles. If you're feeling rich, you can opt for the slightly rarer Unique Pyrovision Goggles
  • Get a HHHH's Headtaker if you want the weapon
    • You can get a clean (tradable one) for 3 keys
  • Get a Spine-Cooling Skull
    • If you have teh monies, 26 keys can get you a tradable one for 23-28 keys
    • If you don't, you can get untradables for 2 - 4 refined + gift wrap