Well here's the emissions components for a '79:
To have a complete 1979 emissions system I think you need:
-'79 carb (which it looks like you have but the air cleaner stud is bent and needs to be replaced)
-Air pump (#1) (which it looks like you have)
-Air rail (which you have)
-Air Bypass Valve (ABV) (#5) (which you have)
-Check Valve (#25) (which you have)
-Exhaust Gas Recirculation (EGR) valve (which it looks like you have)
-EGR cooler (which it looks like you have)
-3 Bimetal Vacuum Switching Valves (BVSVs) (#6): 1 light blue, 1 pink, 1 violet. You have a blue one on the side of your thermostat.
-check valve (#49)
-4 Vacuum Transfer Valves (VTVs) (#8): There are brown, green, blue colors. I have a red one on my '77 but not sure that's correct for '79. You have a blue VTV on the side of your carb.
-A 2-port gas filter (#45) (which it looks like you have)
-2 Vacuum Control Valves (VCV) (#50)
-High Altitude Compensation (HAC) valve (#48)
-1 VSV (#7). The VSV you have (the box with the vacuum lines sticking out of it) is for a '75, '76 or '78 emissions system.
-1 EGR modulator (#55)
-O2 sensor if you're going for full-on '79 emissions. Also need catalytic converters for 1979. Your '78 may or may not need a cat.
-vacuum hose, lots and lots of vacuum hose. It's mostly 3mm, and available in bulk through Toyota (Cdan etc.) or SOR.
Your '78 emissions computer may not talk to your '79 VSVs, so it would be good to have a '79 emissions computer.
1979 is basically a new era for emissions controls, so while there are some things that are common-ish with '78, there are many new parts for '79.
You could probably pass an emissions inspection if your truck is running well and you have your air pump, ABV, air rail, and possibly EGR components hooked up. If it looks like most of your vacuum lines are hooked up to something then you could probably get by. Unless they get suspicious and start tracing vacuum lines.