1983 All Other Makes Recreational Vehicles Smog equipment

I recently bought a 1983 Georgie Boy RV with a carborated GM 454 engine. I'm told this RV is based on the GM P30 van chassis. I am trying to pass smog in LA county in California (the worst place possible for passing emissions, I know). I failed my smog test and need some help before I try again. A second fail here will classify me as a gross polluter and require me to pay more to be tested at a star-certified facility.
The smog technician said the engine is missing the AIR pump, which I am pretty sure this RV should have come with originally. However, the engine has headers with no air injection fittings. I am thinking I would rather weld fittings on to the headers rather than look for the correct manifolds since I read somewhere that GM doesn't have a part number for big-block AIR exhaust manifolds. Is this going to be ok for the visual inspection? I am told that emissions systems components need to adhere to a federal emissions equipment standard, and I don't know if a custom modification to accommodate the AIR injectors complies with this requirement or not.
Another issue is the evap system. The smog-test report shows "OK" on the visual inspection, but "fail" on the functional. I realize this could be due to improper/missing vacuum hoses, but is it also possible that the activated carbon or the entire canister needs to be replaced (does the carbon ever wear-out)?
If somebody could provide an emissions equipment diagram for a GM P30 with a 454, it would greatly help me since it is apparent that previous owner(s) have made all kinds of changes to this thing. There is absolutely nothing relevant on the web regarding Georgie Boy RVs, nor is there a service manual for it that I can find.
I need to bring hydrocarbon emissions down from 1030ppm to under 250, so I have a lot of work to do and any informational help would be much appreciated.