All right! I have emailed Mr. Houge about the OST of Arcanum. I'm waiting for a reply, which might as well never come, but in the meantime I will work on researching the owning rights for Arcanum: The Lost Dungeon of Souls.
For those of you who are interested in what I have written to Mr. Houge, here's a copy of the email.
Hello, Mr. Houge.
I am writing this email to you to request information about who owns the rights to the soundtrack of Arcanum: Of Steamworks and Magick Obscura. As you may know, the game has been released on a digital distribution service called GOG. Through the purchase of the game, buyers are also given a few nice bonuses in the form of avatars, concept art etc. However, the soundtrack is not provided. Given the fact the soundtrack was released as a free download, I was wondering if there would be any problem if the GOG staff would add it to the bonus section of the game, considering the fact many people don't know about the free release of the soundtrack. Furthermore, I would like to ask if you posses any information of who exactly owns the rights to Arcanum: The Lost Dungeon of Souls. The module has been very limited in its physical release due to it being only a pre-order bonus, but to this day there are many people who would like to purchase it at a reasonable price and play it. This information would be very useful towards bringing this module on gog.com. Please consider my questions.