You Didn't say Whether the stripped screws were on just one side or gudgeon.
If not, and they are distributed a bit, then you might look into the
aluminum one peice gudgeons sold by Hobie. They have 8 holes per gudgeon,
which might give you a little extra lee-way. You might be able to drill new
holes and seal up the stripped ones.
These die-cast one piece gudgeons require a little fitting and dremel work,
but might be worth it in your situation.