Interesting...
I googled 16 gauge 1.0 SQMM and it looks like "1.0 SQ MM" means the wire has a cross sectional area of one square millimeter.
One source said the length is critical:
http://www.qualitydist.net/pico-8126s.html
"Fusible Link wire is designed to open a circuit when an extreme overload occurs. Replacement links should be used only to repair factory installed fusible links with the original length and gauge being matched exactly. Typically, fusible link should be 4 gauges smaller than the circuit wire. **CAUTION:**Do not substitute ordinary wire for fusible links and do not replace fuses with fusible link wire as highly technical calculations are needed to determine the correct length and gauge of the fusible link."
Since by now I'd guess most of the links are long gone in our trucks, best guess will have to do on the length...