Update
I contacted an attorney, regarding this situation. Though he could not advise on Indiana law, he did note that most attorneys will not get involved with any property damage only accidents. Basically, my insurance pays on the claim and then goes after the other driver's insurance to re-coup expenses.
The appraiser was out today, was surprised by the extent of the damage. He said there were some factors that were set, ie, as to hourly labour cost, they had to calculate a rate of $100/hour, even though local shops in this area are in the $150/hour range. He stated that he could note that I have a preferred repair facility that has a known rate of $149/hour, so the estimator could use that figure in assessing damage. The appraiser was very candid, he said that the repairs would easily be a 60 hour job, which at the low end would be $6000 for labour and and the higher end would be over $8900. Parts would be very expensive, as the entire rear end would need to be replaced, including the rear slide out, and some parts would be difficult to find. His opinion was that the trailer would be totaled out.
So now in the market for a replacement trailer. I actually found a similar trailer, but without the rear slide out, as I like the basic floor plan (Keystone Outback M28BHS) vs my current Outback 25RSS. Once everything is settled, I can get serious about an offer.