Oil leak: Front Main Seal or oil pan gasket?

My wife's 92 SL1 has been leaking oil out of the passenger side of the
engine for the past year or so. It collects around the lower motor
mount, drips on the ground, and also some gets sprayed around by the
serpentine belt to put a layer of grime on the bottom of the hood.
Maybe a quart or two disappears every six months.

Is this "obviously" the oil pan gasket or the front main seal? I
tightened the oil pan bolts that I could get to and they *were* loose.
I suppose if I do this I may as well just do both, as it seems like
doing either involves pulling the pulley etc. Doing the oil pan gasket
seems like it'd require pulling the exhaust manifold too. I did the
transmission pan gasket a year or two ago when it started leaking but
all I had to do to get to that was pull the battery tray.

Any advice? I have done some front main seal replacements in the past
but they were all with the engine pulled, and I'd really rather not
pull the engine if that's necessary on a Saturn. I think the pulley
can be pulled through the wheel well, am I right? And I don't look
forward to removing the exhaust manifold just to replace the oil pan
gasket. It certainly seems easier to just add oil every couple of
months

Tim.