Glad to hear that you and your passenger were substantially unscathed, Craig! It's not a pleasant thing, nonetheless.
Having had some experience with this (2 accidents-two totaled bikes) I agree with TURBO 100%, as well. If your insurance works similarly to mine, the bike can be totaled out by your insurer when the cost of repair exceeds approximately 50% of the motorcycles pre-accident value. Of course this varies from company to company and policy class to policy class.
Having to replace the gas tank and radiator alone with OEM parts (which you should insist upon, if they even think about making repairs to the damaged parts) will put you very close to that threshold, so I don't believe that you should have any problem qualifying this as a total loss, largely because of the exorbitant cost to replace OEM parts and if you have replacement value collision coverage. if there's any doubt at all about there being either frame or suspension damage you should insist upon experts evaluating (appraising) your Rocket for either or both!
On top of this any aftermarket parts that survived intact and that you can replace with their OEM counterparts, can be removed from the bike and sold. In each of my two cases, I actually made money on the combined parts sales and settlements which enabled me to "trade up" on the motorcycles, i.e., the wrecked bikes were replaced by better, nicer or newer ones with no out of pocket cost to me!
Good luck with all this. Hopefully it will all work out to your advantage, albeit with some measure of bother.