Spent a few hours looking into this. Its not simple. I'm concerned that such modifications may exceed my abilities. It looks like its best to just start over again with a litecoin wallet and built it back up for NDL.
You're on the right track.
Though if you're planning to rebase, going to v0.10.4 is definitely not aiming high.
You'll want at least v0.13.0 where the internal miner is removed so that anti-virus software doesn't flag the wallet and delete it on people.
I have now spent several hours trying to modify the newest litecoin wallet into an NDL wallet. In some ways its easier than I expected, in others, its not. I think it's going to be quite the project, unfortunately. I'm not sure I've really got the time for it, but we'll see. I would have preferred to use an old version of the litecoin wallet (as the most recent wallet I compiled is litecoin based), but if I'm going to have to go through a lengthy process, might as well just do everything that needs to be done to make the wallet worthwhile, right? This will likely require a hard fork though and, depending on the complexity, may require changing some of the parameters (such as eliminating the whole "triple mining rewards once a week" thing).