[OMC-Boats] Upper Gear Case Reseal

(2nd attempt, email tooo big!)
 
Hey guys,

I'm back working on resealing my upper gear case on my 4 bolt outdrive.  The goal is to check the condition of the gears and various parts (they all look excellent!) but most especially to replace those seals where water intrusion is most likely to occur.  Thus far, I have removed the impeller setup and shaft as well as the ball gear shaft (will replace that too since I have it out)

I have attached the applicable schematics from the '65 Parts Catalog.  I'm down to the Bearing Housing (Ref #45 on the schematic) and am wondering if I need to remove and reseal that particular component at all.  I see an o-ring at the top (ref #50) and several oil seals which just happen to be the most expensive seals to replace ($110 for 3 oil seals).  I'm not seeing any source of oil leaks in the shaft so I'm wondering if that would be going too far. 

Has anyone gone this far when attempting to reseal their outdrive?  I want to do it right but ecomonics is suggesting I don't get carried away.

Thoughts?

-Bill
Dallas, TX
1970 Evinrude Explorer - 155 Buick V6 - OMC Sterndrive
http://www.photobucket.com/evinrude_explorer