ST60+ with C120/80 Classic MFD adding DSM250

[tbharty]

I have an existing 2006 boat with ST60+ Depth, and transducer E26030, (an airmar D800 / P17) network to C120 and C80 classic MFD

I wanted to add fish finding capability using a DSM250.

1.) is the transducer compatible?
2.) if so, what connector arrangement do I use to bridge a 3 wire spade connector existing to now go to the DSM250 which has a 7 pin male connection port on the bottom
3) Can I use a sea talk with 7 pin ended cable to go from the ST60+ depth to the DSM250, and then from DSM250 to c120MFD? and switch the ST60+ to repeater mode from master?

thank you

tom