A68 (replaced A67) and older thru hull transducer

[Cp111]

Until last month, my sailboat had a Raymarine A67 with an older transducer. I believe it is an Airmar B744V (possibly even a B44). The A67 died, and I found a grear deal on an A68 with no transducer. Sounded good. I guess I assumed, incorrectly, that an A68 would be a newer version of an A67.

I can't really pull the boat out of the water to put in a new transducer. The one in the boat now works fine. I only need depth from it; I don't need temperature or speed. I don't even need fishfinder display, I just need depth.

So, since A68 and B744 seem to be incompatible, I am trying to figure out some options. I'm hoping someone can tell me whether any of these will work:

1) If I am willing to give up the fishfinder, and just want depth, is there a way to wire the A68 to the B744 directly, and run the A68 in non-chirp mode?

2) Install an i40 Depth, connected to the B44/B744. This seems like a great option for me because I can mount the i40 near my line of sight and see the depth easily. It looks like the i40 depth just has three pins to connect to the transducer, and I've seen B744 as being supported. Will that work? Wiring diagram somewhere?

3) Add a converter (itc5?) to convert the signal to Seatalk ng. This sounds like it would work.. I don't have a Seatalk network, though, and sound like more complication and expense than I'd like.

4) If #2 works, then can I assume that I could run a seatalk cable from the i40 to the A68 to display depth on A68? Not as critical but might be a nice to have in the future.

Thanks,
Chris