Team Fortress 2 Item Drop Chances

Do the various items in Team Fortress 2 have an equal chance to drop? Are you just as likely to get an axtinguisher as a villain's veil?

From the tf2 wiki:

"While it has always been perceived that each weapon has an equal chance of being dropped to the player, it appears that certain weapons that form part of an item set will drop more often or less often than others. It is not known exactly which of these weapons are rarer or more common.1"

It mentions that in the old system the drop rate for hats was 1 in 28, but it doesn't mention any changes in the current system.

In addition to the above answer, you are also limited to the number of items you can get per account in one week. That is why it seems like you get new items when you come back to the game after a long break.

Cosmetics do not drop for Free to Plays until they get a premium TF2 account, which costs $5.00 in USD. Also, I remember back in my Gibus days I once obtained my first taunt: The Director's Vision. I was really excited as well as curious to see what this does. I put it in my special slot (before taunt reels came out) to try it, and I was quite happy I got this item. Of course, me being new to Team Fortress Two, I didn't really know how rare of a drop this was. However, after over a thousand more hours of playing TF2, I never got something like that ever again. From that point on I only received crates, weapons of no special rarity, and maybe one or two hats, still nothing rare.

Also, a quite simple yet true piece of evidence pointing to an irregular drop system is the fact that drops can also be received from gift-o-pults. A gift-o-pult is an item that costs a measly 10 cents on the shop, and only 3 cents on the market, and can be used to package items and send it to a random person. Although the drop system is a more likely way to get loot, this is an essential statistic to count when calculating this question. But seriously though, I never get randomly dropped hats.