Auto Insurance Claims: AAMCO totaled my grooming van and wont pay, auto body shop, small claims court

Question
Here's my dilemma... I purchased a mobile grooming van for $8,300 and brought it to a local repair shop, where I sunk and additional $4,000 worth of repairs into the vehicle.  At that point, the mechanic informed me I need a new transmission, and he had my van towed to AAMCO from his shop.  AAMCO installed the transmission.  On the test drive, they totaled my van!  Completely totaled.  Now, AAMCO's insurance company is telling me they will only pay $3,500 for the vehicle, which they claim is book value (and does not include the repairs, or grooming van conversion).  My total losses, including loss of business, are 5x this amount.  What do I do?  Who do I sue - is it the original auto body shop, or AAMCO?  I am at a loss and can't afford a lawyer, as I am already thousands in the hole and can't pay the loans I took on the business.  Please offer advice.

Answer
Regardless of the "book" value, the van was obviously equipped with more than standard factory equipment and alteration.  There are no books to valuate such a vehicle.  
Even major insurance carriers such as the one that I work for would never attempt to put a value on such a specialized vehicle without first bringing in an outside appraiser who is truly qualified in such matters.  You may be owed a portion of the recent repairs as well.

Now, keep in mind that if you made the mistake of simply paying too much for a vehicle that needed a bunch of work, that falls on you.

You will need to find a qualified, independent appraiser to determine the value of the vehicle and may need to sue Aamco for that amount.  Most small claims court limits are currently at $10,000 and you will not need an attorney.