Nick, the most common method of wallpaper removal today uses a "paper tiger" and either vinegar and an enzyme to attack the glue. The paper tiger is a hand held gadget that pierces holes thru the paper so the vinegar or enzyme can get to the glue. With your grass cloth, you may well end up with having to steam it off, but thy it and find out. A home center has the paper tiger and enzyme, but most reports I have heard say a vinegar solution works as well. You should be able to rent a steamer at a wallpaper store.
However, I don't think that will solve your problem. My guess is that there is a reason there is heavy paper over all the walls and you will find quite a bit if cracking under the paper. There is no way to know though until the paper comes down. Should that be the case, there are several sloutions. When you know what you've got, check at a site called www.ornamentalplaster.com, it think. Brian's regulars are good on plaster problems.