Another clue is the tires - Euskadi.
I'd never heard of these and did a little research. Euskadi is a Mexican tire company whose products seem to be better known in Mexico than elsewhere. You can get some of their tires at places like Walmart and on Amazon, but I couldn't find any source for Euskadi tires in the size that are on this car (175/65R15) - indicating they were probably sourced locally where this latest rebuild was done.
I think the reason you're not seeing many guesses here about the car's origins is that it doesn't seem to follow the trim patterns of any major replica builder.
There are some very nice touches - the paint, new genuine VDO gauges, the hard tonneau, rubber gaskets under the horn grills that a lot of builders don't bother with, etc, etc. (Although the spiffy tonneau seems to sidestep the fact that the car has no actual convertible top.)
But then there's the big disconnect between what looks like a freshly done 'outside', and an undercarriage that shows signs it's been on the road for many years.
Usually, someone building a car for their own use who went to the trouble and expense of doing all of those cosmetic upgrades would have started by refreshing or replacing the drive train.
It's usually only dealers looking to maximize profit or outright car 'flippers' who put all of their efforts into how a car shows or photographs, ignoring the out-of-sight mechanical bits that should be much more important to someone who wants to drive the car.
Again, this may be a solid car, but it's very hard to tell without seeing and driving it or having a seasoned VW mechanic check it out.
In any case, it's still not worth the asking price.