Upgrade from E120 Classic to C125

[Bluedevil]

Chuck,

Thanks for your quick reply. I apologize, but I don't completely follow. When you refer to the "Seatalk Bus", are you refering to the D244 Junction? Also, to connect the E120 as a spur to the SeaTalkng backbone, would I need another converter, or would the the E120 connect directly to one of the white spur ports on the converter using a Seatalk to SeatalkNG adapter cable?

As for the auto pilot computer it is a S2G AST. It does not have a gyro connected, only the rudder and fluxgate. Picture attached.

Thanks,
Stuart