7 years is pressing it. Check it well for dry rot and go from there. For a sense of insurance that you won't have any costly problems. I would replace it. It's not a big deal to do & inexpensive compared to what could happen if it does create a leak.
What Shawn & Stinger said above. I see you have the adapter cable. But they can answer your question about testing the ducer without being submerged. Was it working ok on the 582?