Ok, had the Culligan tech / sales rep come out and look at the equipment. As I didn't want to be charged a service call, I asked about upgrading to one of their metered systems. He remembered installing it a long time ago, looked at it for less than 5 minutes. Small tank is the softener, 2 big ones are the air injection and iron / odor removal. He, however, did not test my water but felt confident enough to give me a quote on a new unit.
Here is what was recommended:
HE Softener Clear Plus system. This all in one system treats Iron, Scale and Hydrogen Sulfide (rotten egg) smell. This system features a built in chlorine generator and chemical injection.
The price for the system is: ~$3,000
9" x 56" softener with 375lb brine system.