Line mode, although accessible by button-code, probably was at one point intended as the final cheat. It's the only extra cheat that does not report as NO NAME. It's finished, and surprising they chose not to include it. They did run out of levels though, for cheats, maybe wanted to be consistent.
(Rick L. Note: Line Mode included in unused stuff because even though available by a push-button code, the codes were never intended to be released to the public. Also, the only other way to activate Line Mode is through Gameshark.)
The micro camera, first of a series of many leftover gadgets. The difference here is that thing actually works.
It can be picked up in a level, so it's possible you had to collect it. The gadget can also be thrown onto a wall, much like the Covert modem. They do indeed look cameras, although not that micro, and Bond would have had to plant them presumably to monitor something.
Perhaps seen in Octopussy with Roger Moore, it was a briefcase with a false bottom housing a bomb. The thing can be picked up, and is just called an explosive case rather than bomb case on pick-up. The things actually work, and more than one can be held (3). They act like briefcase timed mines.
The weapons case, possibly the best beta gadget. It opens up to hold: 2 throwing knives, two hand grenades, and a sniper rifle. This also seems to be from From Russia with Love. In the movie, there's a foldup sniper rifle that Bond was going to use to kill a terrorist leader, along with a popout knife, and a gas canister would explode if opened improperly. Sean Connery was the Bond in this movie.
When you activate the case, it gives you the throwing knives, hand grenades, and sniper rifle as though you picked them up.