Years ago (early 70's) when I was yet a teenager, I worked for Lance
Johnson, owner of the Fargo Organ in Fargo, North Dakota.  At that
time, built several Wurlitzer band organ copies for J.W. McKinnon
(spelling?).  I had the pleasure of doing a lot of work  on some
Wurlitzer 125 copies.  I wasn't directly involved with the manufacture
of the tracker bars but I saw him do it.  I'll try to give you what
I remember.

The main part of the 'bar' was machined out of, I believe, brass.  He
started with blocks of brass screwed to a 'barrel' probably 6" on
diameter.  Barrel with probably four of these brass blocks were turned
on a lathe to make the rounded front.  I'm sure you could calculate the
diameter required for this 'barrel' from the curve of a tracker bar.

For the holes, he drilled round holes all the way through.  Nipples were
soldered to the back side and the bar holes were made square by driving
a square punch into the round holes.

When the unit was completed, he had it chromed.   It  looked extremely
nice when it was done.

If someone wanted to contact Lance, the last I knew, Lance is still in the
organ business, in Fargo, North Dakota, mainly manufacturing church pipe
organs.  If he cannot be found in Fargo from this infomation, he probably
could be contacted through the ATOS (American Theatre Organ Society).

I hope this information is of value to you.

Gary Rasmussen
GRasmus140@AOL.Com