Does the motor run? If it doesn't even try to fire, take the distributor cap off and crank the starter. If the rotor doesn't move, you've got either a fragged distributor gear or the roll pin that secures the gear to the distributor shaft is sheared off. The distributor gear has a hex-shaped female opening that the hex-shaped oil pump drive shaft slides into. So if the gear isn't turning, the oil pump won't turn either. This would be the easiest thing to fix, although if it were me I would still drop the pan to remove the broken bits.
If it's a sheared roll pin, the most likely cause is a piece of valve seal got into the oil pump and locked it up.
If the rotor turns, then I would check for sure that there's no oil pressure. A wiring problem or a bad sensor can make the pressure gauge or the idiot light give a false indication of no pressure. For this check disconnect the plumbing where the oil pressure sender screws in (probably at the front of the block down low on the driver's side) and crank the engine to see if there's leakage.
If there's no leakage, and if the distributor rotor is turning, then you need to check for a broken or twisted oil pump shaft. (The shaft can twist up like a licorice stick and get too short to keep from falling out.) Take out the distributor and look down inside the hole and look for the hex-shaped male shaft.
If it's there, then you've got a big problem, that somewhere there's an internal "leak" that's letting all the oil supply out. Good oil pressure requires that there be something for the pump to push against. If all the oil is escaping through a wide-open leak, then there's nothing to push against. Possibly a bearing shell has been spun and ground down so thin that the oil that comes out the galley at that bearing is escaping out the sides and robbing the oil pressure from the rest of the engine.
If this is the case, no externally jerry-rigged oiling system is going to help. Also, if your problem is a busted oil pump drive shaft, it's might be just a matter of time before the crank catches one of the broken pieces and flings it hard into something else, totally fragging your engine and leaving your RV conversion stranded in the middle of nowhere.
I don't know how much of this makes sense, and your comments about how hard it would be to drop the pan indicate you don't have much of a commitment to actually fix the problem. So I don't know why I typed all this up. Guess I was just bored (as usual).