Why has the car been sitting so many years unused? Is your intent to restore it at some point including body work and paint? If so, I would get an estimate from the very reputable shop for the metal repair and get that cash. Put that away as a "credit" for when you undertake the work. Now, if you have no intent to restore the car but just get her running at some point to enjoy, I would have a reputable shop repair to pre damage state and let the tow driver pay.

You're going to need an advocate. You're going to need someone to represent your interests.

If the car is insured that would be your insurance company.

If the car is not insured this gets a little more complicated.

If the shop is insured and you let their insurance company handle the claim you're basically screwed. The shop's insurance company will want to keep the claim as low as possible. The have no interest in keeping you happy.

This is why I'm big on always keeping my own insurance policy on my car. Project car insurance is only around $100 a year.

Richard Newton
Project Car Insurance

No way I would let the owner's dad's shop touch the car. Take it to a body shop of your choosing that works on old Porsches. Not a collision repair shop.
As an aside, I wish all members would at least put their city/state in their posts if it is not in their member info. Makes it harder to offer up advise w/o that information.

Update. Took it to Renown Auto Restoration in Schertz Tx. They did the job. Found a careful tow driver. I lost a few hundred dollars but their insurance paid for the majority of the repairs.