This.
Most insurance companies don't go by KBB anymore (KBB is honestly worthless and has been since like 1997). They go by what similar vehicles are selling for in your area (known as replacement vehicle value). If you can come up with a list of similar Jeep for sale listings, that will help negotiate the value. Like you said the add-ons likely won't count unless factored into your policy beforehand.
Once the value of it is determined, you can proceed with buying it back, which will mean they will likely deduct the salvage value from the amount they give you back for the Jeep. So you'll get the Jeep back plus a certain amount of money that they determine, which will be negotiated value for a totaled vehicle minus what the salvage value is. I understand it was your father's Jeep and you would want it back and fix it. It does look fixable, I mean anything is fixable with time and money but it looks doable. I do think that is totaled though, just from the damage and from the age of the Jeep. Usually anything that costs 60% of the value of the vehicle to fix is a total loss. I was an insurance adjuster for a bit after college. Any hit that pushes a vehicle 20-30 feet is a hard hit, the person that hit it must've been flying. I'd want the frame checked.
Edited because my phone keeps hitting send before I finish typing.