[JURY]

Use a paint scraper to work behind the plate ans loosen whatever someone put on it. Make damn sure the power is OFF! If that scraper slips behind and connects to a power wire all hell is gonna break lose.

Thank you, Sans Peur and Captain for your replies. I used a serrated thin steak knife ( thank you, my wife) and a mallet and was able to remove the plate without damage to myself or the vessel though the knife may never be the same again!!