You're welcome!
If your truck's existing front light / alternator harness is still in good condition, you could modify it to work with the gauges by re-locating the brown wire to the appropriate cavity in the bulkhead connector and adding the red wire for the ammeter (with an inline fuse) to the junction block on the horn relay.
But if it's not in good condition, reproductions of the 63 gauge type front light / alternator harnesses are available from either
M&H or
AAW in their "Factory Fit" series. They're typically listed in the catalogs as a "forward lamp harness" or "front light harness".
It looks like M&H and AAW are both offering 3 versions of these harnesses that will work with gauges. One is for use with the stock type externally regulated alternator. The other 2 are pre-modified for use with newer SI series internally regulated alternators (one is for driver side mount and the other for pass side mount).
The cab harness (often called a dash harness) is also available as a reproduction. But if your existing cab/dash harness is in good condition, it is fairly simple to modify as I posted above. I forgot to mention it earlier, but the terminal you'll need to crimp onto the resistance wire is a Packard/Delphi 56 series female terminal. They're available from a number of sources including many local auto parts stores.