I may convert the codes over from the other NTR plugin at some point. I actually came up with some other codes as well, including infinite fuel for the vehicles, however, I've since become pretty busy with work so I've been unable to dedicate as much time this scene.
However, if anyone is feeling ambitions and would like to pick up where I left off, the following are the memory addresses I found:
00492BA0 heli 1/3
00494F78 heli 2/3
00494264 snowmobile 1/?
00491B28 snowcat
00493360 snowplough
In terms of removing the online play limitation, I'd search the forum for how to make a NTR plugin and go from there. I believe this to be a good exercise to anyone interested in learning more about the inner workings of these games.