The Motivation;

Same motivation that caused you to install Galv. Pipe in your Boom; It
was broken. :^)

Lower priced boats developed leaks around Keel Bolts thru the GRP Bilge.
The working of the bolts and nuts narrowed the thickness of the hull.
The cheap way to repair ( Like pipe in the broken Boom was to move the
keel bolt, after sealing the old holes, to firmer sections of the hull.

This caused many of the Coranados to be scraped or sold for give away
price.

It was a boat that was built to a market price. Many cheap things were
done to meet a price.

Ole Thom