My observations. Please do not kill the messenger, I will be frank in what I see and I sometimes get in trouble with my comments.
A potentially nice car to have fun with, but there are obvious issues and questions that need to be answered before one can come up with a value.
Since we are not talking show quality points car we need to know about how well it drives. Kind of a first question, can you take this car out on the highway and run 55 MPH for 4 hours straight and feel comfortable driving it? Who rebuilt the engine, was it balanced, did the guy know how to do babbitt, what parts were new and what was thrown into it used? Same goes for the ****** and well every other moving part. Too often either the wrong type of repro part or a 'slightly' used worn part is put into the rebuild of a driveline.
I know of a few people who bought 'restored' cars from reputable shops. The cars were dogs which were not reliable nor able to run the 60 MPH a properly restored car should be able to run without batting an eyelash. So $8000 to $10,000 later (the guys had to pay others to do the work) they had a car that would go anywhere.
So that is one factor when looking at a car like this you must consider in the value. Quite frankly running is a meaningless factor. I know of running engines that were essentially scrap metal.
Now the body, lots of questions that should be answered. As a cabby owner I know what to look for in a body. A cabriolet is unique in its construction and you can not look at it like you would a coupe. The 68B's have potential wood issues. How tight are the doors? What wood was replaced? Are the bows close to correct? Why is the passenger side landau not locked? That can be an effort to correct. That could mean a loose hinge on the landau or the geometery is wrong. If the hinge is loose then after you fix that then you might have to move the upper or lower bracket to correct the problem. Of course the big question, are the correct cabriolet parts there and restored in such a way they are working. The body is essentially a big 'device' and the parts have to work right. So how do the doors close? Does the body pull funny when you put the top up or does it snap funny when you take the top off?
I will also add that body in the pictures does not look right. It could be the angle of the pictures. The reflections on the passenger side do not look even like the metal is not evenly curved. The rumble lid gaps do not look right like the side of the qtr panels might be pushed in a bit (guess how I know this, it is a problem my car had). But again these could be issues with the pictures, but none the less it raises some questions that need to be answered before I would consider the value of the car. To correct the issues would not be cheap. It also leads me to question the overall quality of the whole car.
In my mind the car smacks of a potential fun car, provided the body was not some horrible mess thrown together. It presents well, but is not something you have to worry about. Drive and have fun. Since it is cabriolet that puts the value starting point at the loosely $20k mark for starters. Experience tells me that the mechanicals are not where they should be (but I could be wrong) for what a Model A can do. That thrown in with the issues that might be found in the body, this starts dropping the value.
So depending on an inspection the value can range widely from $10k to $20k. Properly restored the value ranges from $20+k to $30k of course depending on the market, but you would need $20k to get this car to the $30k mark (doing it right is NOT cheap). Plus this depends on the body being fairly unmolested or good metal work.