I'd reccomend his shop any time.
The guy got me into 'wheeling a loong time ago, and has helped me out of some tight spots when he had spares and I needed them. I'm suprised he hasn't read about my rig being for sale, he isn't too far away and he'd do well on the parts...
I'll be watching...
I do believe that the plug shown, given it's proximity to an unused set of mounting bolts on the firewall, indicates that it is for plugging in the Air Conditioning Main Relay that would have been mounted on that unused set of mounting bolts, if that '79 had A/C.
My '79 has the exact same...
If you want to build one similar to that...
<shameless plug>
Check out the Vehicles For Sale section if you want to build a similar rig - I've got a '71 factory soft top rig and a PTO winch setup for sale... :-)
<\shameless plug>
Seriously, that is one cool rig. Not often you see an...