David Repanshek's query jogged my memory. Years ago I found it
necessary to make a replacement tracker bar for a larger Wurlitzer
instrument. After having made one of phosphor bronze, I decided that
was just too much work, so this next one was different and a whole lot
easier to make but almost as durable.
Simply stated, I made it from hardwood and installed all the proper
nipples, and then to make it durable I used thin brass and made an
overlay for the front. Using a small hand brake, it was easy to shape
the overlay to get an excellent fit over the hardwood. Small brass
screws in the top and the bottom secured the overlay to the hardwood.
That made it easily removable in case that it should be necessary to
replace the leather gasket under the overlay.
I hope this is clear enough to understand.