Yes. IMSLP only hosts works that have been verified as being in the public domain. For the US that means anything that was published before 1923 can be freely distributed. Other countries have a copyright term of the life of the author plus 50 or 70 years. For works in the US published after 1923 the "life plus 70 or 75 or 120" applies depending on how and when it was published.
So since this file is a scan of the 1904 edition it can be freely copied. And since Simandl died more than 70 years ago it is also free to download everywhere else in the world.
Now if someone comes along and does a "revised edition", like Lucas Drew, or Zimmerman, or Levinson, then those revisions have new copyrights and it gets more tricky, but that doesn't effect the copyright status of the original unaltered material.
Another example: companies like Kalmus do exact reprints of editions that are public domain. This is not a revised edition or an edition edited by someone with new markings, but rather an exact reprint of a work from before 1923. Sometimes companies will then put: "Copyright 2012" or whenever the year they made the reprint to make people think they have some rights to the edition but in fact they dont and this scare tactic is referred to as "copyfraud". Unfortunately, it isn't illegal to falsely claim something still has copyrights, so sometimes things that say they are copyright can actually be freely distributed.
So you could do whatever you want with this Simandl file - even print it out, bind it, and sell it online for $25 plus shipping, because its copyrights have expired and it is now in the public domain.
If you're curious about copyright IMSLP has a great page about it to help clear up a lot of myths:
http://imslp.org/wiki/IMSLP:Copyright_Made_Simple
