Thanksthis page is too your drive by serial number
Mercruiser (Alpha One, Gen Ii Sterndrive & Transom Assy.) Engine Components
www.marineengine.com
there are pages for both the driveshaft housing (upper) and gear housing (lower) on each page is a seal kit for each one, they may also have a complete kit for entire drive
I drained itMust be a major leak if water is showing up in the monitor jug.. I would drain the drive ASAP.