Small amount of oil in water intake

[seandogrocket]

Where do I start. Had the lower unit seal fail about 2 months a go. Since I am a cheap bastard, had my mechanic replace the lower unit with a used LU. On the second trip out engine stalled while on a plane 3 times. Took it in and worried that the lower unit failed again. When I went to flush the engine with ears, had no water coming out. Turned off engine off quickly. Dropped the lower unit Saturday and found a 3/8 piece of metal in the water pump. Impellar was pretty tore up. I now hate my mechanic. Replaced the water pump myself and had good water flow with the ears attached. Today went to check the lower unit oil to see if it had any water in it and first noticed a small amount of oil coming out of the water intake. Then drained the LU and had lots of water come out . Feeling like I may of destroyed my engine . Big questions are what could of caused oil to come out of the water intake? Second is it possible to replace the lower unit seals? 2000 200HP 2 stroke saltwater series. Thanks

[boats.net]

Probably have a drive shaft seal leaking in gearcase, but need to see if find out where the metal in water come from. Did you see any metal fragments on bottom drain screw magnet in gearcase when changed oil? If so then may have damage in gearcase.
The drive shaft is not hard to replace but probably better to replace all gearcase seals.