I have not been following the nipple discussion but I have antique
tracker bars with the nipples soldered in them, 90 or so nipples
in each bar.  A little heat, pull them out, and off you go.

If nipples were 25 cents each then the trackers would be $20 each.
I will put them on my web site, or just contact me if this idea
is interesting.

Alan Erb
http://www.mechanicalmusicbox.com/