Sorry - I have NO idea what a "Shaw's Fireclay" sink is...

However - you stated that your husband installed (cut) the marble; and cabinets, etc. for this installation.

Suggestion. The sink is gong to be replaced. Contact Rohl's or Shaw's and ask for permission to destroy the sink being replaced. Have Rohl's come on out and take a look.

Remove the plumbing, garbage disposal, etc. Then using some select instruments of destruction; cut the sink into some pieces and remove it. You can slide some THIN material under the sink edges to make cutting the sink flange easier without damaging other stuff.

Once the sink is out in pieces - you now have more access to the marble edges - to try and get those up without damaging them. You will have to remove any Marble or Cabinet which would prohibit removing the sink WHOLE. Since a new one is being installed. But with the old one removed in pieces - it might be easier to accomplish this task. However - Marble breaks very easily; and you are probably going to have to be redoing at least some of the Marble pieces...

D.