Originally yes, DD off-road business bought by MTU in 2006, then bought by Rolls Royce in 2014. So technically, I guess need a RR tech. Yikes! ;-)
Any real Detroit shop can work on them. I enjoyed what work I did on them. Mostly hang on stuff. What services are required.
I have been using AMT. They have a satellite shop up here in CT but based near you. American Marine Tech, Inc. 2225 Idlewild Rd. Bay 2 Palm Beach Gardens, FL 33410 Phone: 561-691-3388