That doesn't look like the stock engine control panel seen on most of the J/30s. Look at this link, page 24 and the schematic on page 56:
http://j30.us/files/Rhapsody/yanmar-manual.pdf Most of the J/30 Yanmar engines use the "B" style panel. The sensors you were sold probably work with the idiot lights on this panel. I think you'll need to research the individual instruments on your panel and find the matching sensor that goes with them.
Bill
Rhapsody #348
ps - I like your panel better than the idiot lights!
[This message has been edited by whk (edited 05-07-2007).]