Finishing the Pad
The last step: attaching the belt.
Mark the 10 rivet entry points on your pad (see pictures above). Measure out your belt and cut it to the right length. Punch 4 holes on each end (aligned with the 4 markings you made). Unfasten the belt. The part with the buckle should be attached to the front, and the part with the holes should be attached to the rear. Attach the belt to the rear with 4 medium rivets (you will need a nail or sharp instrument to puncture the padding). The front will eventually be attached with 4 rivets, but you will only be putting in 3 medium rivets (the 3 most medial rivets). The fourth will go through the pad, the belt and your jacket (see below for more instructions).
You are now done with the pad!
Attaching the Pad to the Jacket
You will need 3 large rivets and 3 fender washers (large washers with small holes – the hole needs to be smaller than the rivet head).
There are 3 areas on the pad that you will be riveting to your jacket. These are: the remaining 2 points on the rear of the pad marked in the picture and diagram; the 1 point on the front where the most lateral rivet was suppossed to go.
With your jacket on, have someone place the pad on your shoulder and mark the exact 3 points on your jacket that line up with the points on the pad. (This will require some judgment on where the pad looks best on your jacket.) You will need to make tiny holes in your jacket at these 3 points. These holes should be small, just big enough for the stem of the rivet to pass.
Take the larger end of a rivet and place a washer on the stem. Stick the stem of the rivet through the inside of the jacket, straight through until it pokes out of the outside of the pad. Set the jacket on a hard surface. Place the smaller end of the rivet on the end of the stem. The 2 ends should loosely snap together. Using a rivet punch and a leather or wooden mallet, apply several blows to the head of the rivet until it is firmly in place (if you don’t have a rivet punch and mallet, using a metal hammer directly on the rivet will usually also work).
Repeat the above step until all 3 rivets are in place.
Note: I have not actually tried this exact procedure before. Please let me know if the 3-point-attachment works for you. This seems like the attachment method in the movie, and it seems to make sense. It should theoretically hold the pad onto the jacket well, but only experience will prove this.