Our dwarf pink grapefruit and dwarf blood orange seem to have created
a really delicious fruit resembling a navel orange but tasting like a
sweet pink grapefruit. The flesh also has a uniform pink color like
the grapefruit, while our blood oranges are spotty red. My question
is: Detailed instructions on propagating this interesting and
delicious fruit?

Contact your local agriculture extension agent.  Its free, we pay
their salary through our taxes. He or she will explain or show you or
possibly conduct classes on grafting fruit trees.(and they generally
like what they do!) Best of luck, hope this will make you a million!

I have absolutely no background in agriculture, but based on pure
common sense, I think that if these new fruits have seeds in them,
planting the seeds should produce plants that, when they get old
enough, should produce the same kind of fruits. Don't they?

Anyway, good luck and I'm looking forward to the opportunity to taste
one of your new fruits some day.

Sam

Perhaps these sites will be helpful to you.

http://edis.ifas.ufl.edu/BODY_XC004

http://www.floridagardener.com/misc/citrusbudding.htm