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).