Everyone and their grandpa knows that at this point you do NOT have permission to use the artwork. This is how copyright works, it doesn't expire or get abandoned even the author cannot be reached.
That is how it legally is. That doesn't mean that we all agree that is how it should be. Nor has it been like that for very long.
Copyright as it became inshrined in law in the US and most of Europe at least, was intended to provide a time limited incentive in order to encourage innovation and creation. Once it does not serve that purpose, it may still legally be wrong to reuse a work, but morally there is no longer any need for the work to be protected and there's little reason to be concerned about it.
It may not have been a very classy move, nor legal, but on the other hand I completely fail to get even slightly annoyed that someone took an image that has been floating around for years, that has minimal commercial value for the original artist, and put it on their site after allegedly trying to contact him and failing to get a response.
He's taking a legal risk, and that is all on him.
I'm even conflicted about the removal/restoration of the artists name. On one hand it seems disrespectful. On the other hand, is it better to leave the name on if the artist may possibly object to being associated with a commercial venture?
In many countries, such as Norway since that's the case I know best, copyrights and creators rights are separate. That is, you can give/sell/rent copyrights, but creators right *always* remains with the creator of a work, and they include both the absolute right to get credit for your work if you wish, but also the right to have your name taken *off* a work that you feel have been altered or used in such a way that it does not reflect you.
Arguably, in some cases, if you are prepared to take the risk of using a work you have not secured rights t - whether or not that is justified - it may be morally the right thing to do to consider whether or not to remove the name of the creator of the work as long as you don't know the wishes of the creator of the work.
As for restoring it - since the community has in this case plastered the name all over the place, that pretty much removed any reason to keep the name off the image.
Frankly, unless Marko Hirv shows up and raises hell over the abuse of the image, I don't see the point of caring about this.