Topic. If I find one at level 5 will it be the same as level 50?

Yep, it'll be the same no matter when you find it.

Here's a list of all leveled items - http://uesp.net/wiki/Skyrim:Leveled_Items

What about daedra lord artifacts? The one I am looking for isn't on the list.

Mehrune's Razor and so on? They're not leveled.

I don't understand the term. So that means their damage and powers will scale to your level?

Levelled does mean that, not being levelled, however, means the opposite.

It's quite amusing how little levelling is present in this game actually. However, there is a trick. Often you receive a renamed levelled item as a unique one (e.g. Blade of Winterhold etc.) which does count as levelled.

Sorry for some reason I have difficulty in following this term.

So let's say, Mehrune's Razor as an example. If I find it at level 5, will it have the same stats as if I had found it at level 50?

yes it will. all items you get from deadric princes are static. they always have the same stats no matter what your lvl is when you get them.
their are actually only very few items that are leveled when it comes to the very few uniques that are out there. in exchange any other thing even vendor loot became leveled. sigh. there is a good reason why leveledthesda should be called like that forever. they dont learn from thier biggest mistakes it seems.

Yes it will have the same stat and that means that Mehrune's Razor is unlevelled.
In another word its level does not take into consideration the level of the player and the stat of the item will remain the same as when found throughout the game.

Hope it's clear

Yes it is thanks.