How is this guy going to title this car without a bill of sale.

Selling real estate I've used this clause:

At Closing, Buyer shall receive a repair credit against the Purchase Price in an amount equal to $X for repairs and replacements at the Property. Said repair credit is the total agreed amount between Buyer and Seller as offset the repair work found during Buyers completing due diligence inspections of the property. Seller nor Buyer shall have any obligation to pay the other party due to any increase or decrease of the actual cost of the repair work compared with the credit given and said credit shall not be subject to adjustment.

As it seems it may be difficult for you to communicate with the buyer about what you said "It was older restoration but still looked great."
All the writing on this site does nothing to resolve. Before the deal completely sours and with the potential to spend a lot to resolve think about a fairly easy fix.
The real estate deal requires inspections. The sale from a far requires trust and facts (there's that word). The problem is based in interpretation of condition and the private discussions we are not privy.
It's tough to communicate about these deals. I'd recommend the easy road of communicating and getting his list and what he wants. Then you develop your counter and get him to accept.
Or, don't and see what happens.

This comes too late for this deal, but I have learned through selling hundreds and hundreds of used cars, trucks, vans, and motorcycles including classics that the deal is going to go down MY WAY. Not their way. That doesn't mean that I won't make some concessions to them to get the deal. But overall, the deal will be done my way and all documents that I have will be executed to my satisfaction. And one document in particular that the buyer has to sign and is all by itself with no fine print is AS-IS NO WARRANTY. A full page that has only that and the vehicle's description on it.

Now recently, Illinois has stepped in and forced a warranty on some used vehicles. That played a role in our deciding to go exclusively to 'rebuilts'. They are exempt from the State's mandate.

There is not much the OP can do at this point except wait for the buyer's next move. As I said before, I certainly would cease all communication with the buyer immediately. Whether the time is right for an attorney is a matter of opinion. It's only money.

Just out of curiosity,
Do you have ANYTHING in writing, an email, the original ad etc. that states the car is being sold AS -IS?

I will mention the following for others: I've learned in the last 25 years of being in business that People who are in a rush to get something done almost always turn out to be A PROBLEM.
After having experienced this 5 or so times, I noted it was a common trait these people seem to have
After noting this, It became a BRIGHT RED FLAG that I will not ignore, and send them elsewhere.

I have text messages that you must sign the bill of sale.
He said he would and scan it and send it back. I said I want to fax it to you now and both him and the guy who looked at rhe car stated they don't own a fax machine.

I have text messages that you must sign the bill of sale.
He said he would and scan it and send it back. I said I want to fax it to you now and both him and the guy who looked at rhe car stated they don't own a fax machine.

Don't sign it without him signing it first. I don't know what that matters...maybe not at all, but if he wants to play head games, play 'em...
It sounds to me like maybe now he needs you...

You need to step back from this and get focused on what you can control. Worrying about what texts you have about an unsigned bill of sale isn’t going to get this to go away. Sure, save those, but as tjp said, a court may laugh at that as anything to be concerned with.

Cease communications until you speak to an attorney, and focus on finding one with experience with such a mess. Or wait until his sends a letter and then get one. These are things you can control. If you want to ask him what it will take to “make this right” to get you peace on the matter, that’s another thing you can control. Personally I would see if he moves on before doing that one.

History of the future- if he’s a game player with means or an accomplice attorney(himself, brother, friend) he can shake you down. A lawsuit will cost at least 15k. For you. He may not face as much if he has the right setup. The game will be chicken to see who will shell out the opening salvo in court, or see if the other guy coughs up 5k to make it go away. He’ll drum up a 30k invoice for a paint job, parts missing, engine work, etc. so you will have to choose to fight on principle or pay a lesser amount to get away from him. Will a judge or jury have knowledgeable car people that will see the issues with understanding, or will they see pictures taken to accent a flaky spot or rust on the back of a bumper and see it as you sold him a lemon?