An interesting project came in a while back. The instrument is called a MELOBAR, a lap steel style slide-guitar with a canted fretboard to allow for easier playing both seated and standing with a strap. David Lindley is known for playing one in his project El Rayo-X. They were designed by Walt Smith of CA in the late 60’s, and this one seems to have been made in the late 70’s.
The string spacing and string height was all out of whack at both the bridge and the nut, making it almost impossible to play with a slide. There were various pieces of shim material keeping the strings at the right height, but they really hurt the string tone. Also, the customer wanted his Melobar to have 7 strings instead of the original 10. You can see there were even more slots than that in the nut and bridge. Perhaps someone tried to even out the spacing back in the day.
Both the nut and the bridge are made of aluminum so I started by leveling them out, eliminating the old string slots. Once I had a nice flat surface sanded to 800 grit, I laid out some lines for the new slots with my STEW MAC slotting ruler and filed guide notches which I would open up later for the proper string gauge. When laying out the strings I was careful to space them wide enough at the bridge for comfortable picking with bulky fingerpicks, and made sure they laid nicely over the pickups.
With the strings back on I filed the slots level, tuned up to pitch, and got out the slide. The Melobar now has a great clear tone with level strings making it much easier to play slide on.