Regarding Calipers - you can buy perfectly good dial type from
Harbor Freight Co, in Camarillo CA for under $20. To receive
their catalogue call 1-800-444-3353. They also have diamond
grinding bits and many other tools that are handy for jewelers, a
lot of their tools are imported from China. I have checked their
calipers and find them quite accurate. I use them all the time
for layout work on silver as an accurate scribe. Just use a
permanent marker to darken the surface and use the points to
scribe away, use acetone to clean up the silver, be careful of
flame as its is highly flammable. To see the results of accurate
work check out my web site at
http://www.artsights.com/burtondesign to see some of the boxes
I have produced using a caliper and my “GROOVY” TOOL to cut the
grooves for bending the silver. John Burton