A closeup would help. Probably just a reinforcement.
Aas already mentioned the Ammeter hookups are with ring terminals and MUST be insulated from ground and all other circuits.
All of the wires connected to the battery are hot. The ammeter is like a section of wire, except its a metal plate with two studs.
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The '68 Dodge Chassis manual probably shows the boards if you need reference. Also how to take it in and out.
This is from the assembly manual and shows the routing and support.
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