Here's one at Ft. Pierce. Not too far down the road.
DAVID C. ROBERTSON, AMS
YACHT SURVEYING & CONSULTING
3415 North A1A, Ft. Pierce, Fl 34949
Phone: 772-342-5833. Fax: 866-927-0567
Society Of Accredited Marine Surveyors
For engines, call Capt. Tim at Florida Marine Diesel.
He is also in Ft. Pierce.
He is good on Yanmars. I don't know about Cummins. If not he should be able to point you to one.