Pinball Resource in the USA, is the sole licensed supplier of Gottlieb parts, and Schematics. You might find a used schematic for sale some where.

For the glass there are a few options. First, if you can find the correct fitting used glass, possibly on a pinball ad site in the UK or in Europe. You can also have a local glass shop cut, edge, and temper a new sheet of glass. The dimensions of the glass will be in inches. You will have to decide on which is the best money spent on your game, New or Used. You could make a template with a large piece of cardboard.

Gottlieb EM incline is built into the game. Get under the game, better with a friend, take a level, and check the level along the edges of the cabinet sides.
The feet are called levers, there will be a nut, and the foot with the threaded shaft rotate up and down. Some times they will be rusted and stuck. When the bottom is level the playfield will be set at an incline. Most people will raise the rear of the game 1 to 2 inches higher than the factory setting, for more speed, which can lead to quicker ball play.