It lookes perfectly similar. Apart from the carpet/leather on the bottom part. Seeing how he went for the racing seats, maybe he actually likes the clean race style interior.
My bad, the picture I chose of the actual Countach interior admittedly isn't the best choice for displaying the differences.
But consider on the replica:
* those horrible, large, angular (plastic?) pieces on the floorboards/sides
* lots of visible rivets/screws
* center console on the floor is very different
* overall visibly lower quality materials
* the seats appear to be fabric instead of leather
* ugly Radio Shack level rocker switches and buttons
It's just more reminiscent of a racing interior (someone compared to an F40) than a Countach, which was perhaps minimalist, but stylish. (I won't make reference to rich Corinthian leather.)
Again, I don't mean to take away from his achievement...it's probably the BEST Countach ever built in a basement!