Cross-Region Gifting Questions [GAs over, solution added]

Here's the situation: I have a few gifts in inventory from before Valve stopped doing that. I want to give them away, but I can't figure out if they're region-restricted or not. I've tried researching it, but all I can find are Steam Support pages (which are a little vague for my taste) and threads complaining about not being able to gift to the US any more, and frankly it's giving me a headache. If anyone has any experience in this, I would love a straight answer to any of the following questions:

• Is the gifting restriction based on currency conversion only, or on the price of the gift in question?
• Is it true that you can give to cheaper countries, or are you locked into the +/- 10% range? (ie: I live in the US. The Euro is more expensive, so I can't gift to the EU. Could I gift to, say, Mexico though?)

And probably most importantly:

• Valve says that when I hover over the gift in my inventory, I should see what region restrictions it has. I see none at all. Does this mean it really is safe to put it up as non-region-restricted here, or are there restrictions that Valve "forgot" to mention on their support page? Because frankly, Steam is pretty buggy in my experience and I wouldn't be surprised if they messed it up.

Thanks for reading, and double thanks if you can answer! Have a small 1+ puzzle train for your trouble, and have a nice day!

edit: Thanks for the answers. It seems it should be safe to give away the games I have in inventory unrestricted, so I've added one of them as a bonus giveaway below.

Rambling about the Puzzle

Apparently the puzzle is a lot harder than I expected. (That, or very few people read threads without the [GA] tag.) Since I do want people to win these games, I will start supplying hints on a periodic basis whenever I feel like it. But first, a story!

I used to be a lower-tier admin on a MUD back when they were popular (and indeed, long after they stopped being popular). Perhaps the biggest rule we had was "No spoilers for quest solutions!" And as a Celestial one of my biggest duties, aside from reminding people to watch their language (we had some younger players and tried to maintain a family-friendly environment), was to provide hints to people who were stuck. It could be difficult at times, finding the exact level of help a player needed without just giving them the solution, and I, well, I developed a reputation for being on the cryptic side.

So imagine my delight playing The Talos Principle: The Road to Gehenna when one of the NPCs recognized my character and said something to the effect of, "Uriel? You mean the Messenger that gave the most cryptic 'hints' to all those puzzles? You're the worst of the lot!"

I have never identified more with a videogame character.

Which is to say: I apologize in advance. I am probably going to give the worst hints ever, but I'm trying! Good luck, all.

Enough backstory, where are the hints?

First hint: Technically, it probably should have been written as 11111+puzzle.
Second hint: 11111 has five digits. What else has five "digits"?
Third hint: -1 only has one digit.

Giveaway's over, so here's the solution:

The solution is to treat the five-character code in the puzzle URL as if it were a number. Add 11111 to that "number", and you get the giveaway code. There were a few twists: -1 might be a little confusing, being two characters long, but the number -1 only has one digit. Letters in mathematical formulas are usually variables, but in this case we just move to the next letter in the alphabet, so A+1=B, B+1=C, and so forth. Put it all together and you get something like this:

  1  1  1  1  1
+ B -1  A  2  A
---------------
  C  0  B  3  B

Plug C0B3B into the giveaway URL, and voila! A tiny train.

Bonus giveaway:

Gift copy of Don't Starve Together up for grabs, thanks to your help.
Hint: Whatever you do, do not divide by #!