Dave Tardiff actually has one of the tools for attaching the Clipper belt lacers to the ends of a leather belt.
Here's some pictures he graciously allowed me to post:

 Logo on Clipper tool

 Side view of Clipper tool

 End view of Clipper tool


The next picture shows the tool next to a smoothing plane to give some idea of its size:

 View showing scale



Here's Bruce Zenge's description of how the Clipper tool is used:

The lacing comes on a card with the individual laces lined up side-by-side
with spacing between each lace.  Looks like a long pyramid with the sharp
points inserted into the cardboard.  The tool is "v" shaped, hinged at the
bottom, with a series of slots for the top part of the pyramid to fit into.
 Each metal lace has its own slot.  These are spaced equally, so the
opposite lace can fit between each pair on the opposite end of the belt.

A metal rod is inserted lengthwise through the laces in the tool to hold
the laces in place, and the tool is squeezed together while the end of the
belt is placed between the sharp ends of the laces.  (A vise is used for
this.)  After the lacing is firmly closed on the belt, the rod is removed,
laced end of the belt is removed from the tool, and the process repeated on
the other end of the belt.  After both ends of the belt, the rawhide or
metal connector is cut to length, the belt installed on the machine of
choice, and, as they say, Bob's yer uncle.