Quoted from KenLayton:

Great idea to use hairpin clips! I would have never thought about that. Makes servicing much easier.
Where did you purchase the xylophone bars and cushions?

Quoted from CactusJack:

You will never get a better sound than with a Gottlieb or Bally Chime assembly as they both used "Tuned" sound boxes below the chime bars. They are ported and the compartment is tuned to the notes. This produces sound waves that come back out of the sound box and cause the chime bar to continue to resonate and produce a sustained and louder tone. Williams cheapened out and simply used an open box which does not trap as much of the sound and does not feed it back as well to the bars. In fact, each strike of one bar causes the other ones to "join in" producing the sound that is unique to Williams. Using your narrower Xylophone bars allows even more to leak past the bars and kill the resonance to some degree.
The clank of a williams is just a matter or restoring it to all the proper parts. Specifically the foam washer that was used below. This keeps the bar from rattling on the frames. The neoprene tubing keeps the bar off the stand ups and the upper parts pin it down to reduce its ability to sway from side to side (edges striking the frame).
From what I recall, Williams and Gottlieb used Aluminum bars. Bally used steel ones which cause them to have a different sound too (like your Xylophone bars).