I guess you have never been to USS in person? you can clearly see & run the cars when you are there, so yes you can tell if its fit to drive away. cant really do that from an auction picture.Thats not always the case though...
A friend of mine back in Scotland did the whole Japanese auction 'thing' and ended up buying an R32 GTR of remarkable quality and shipping it to UK..all on the back of 2 pictures and an auction info sheet. Once car was picked up it turned out to be a beauty with a substatial amount of aftermarket parts on it which had not been declared on info sheet.
As with any auction, in the UK or anywhere around the globe, you take a chance. Its equally true to say that even being there in the flesh and seeing the car is no guarantee that it will be fit to drive away from the auction house.
You can pick up a diamond or a dung'er....theres only so much you can do to sway the odds. At the end of the day its a gamble you take and it CAN pay off. Ive definately made a net profit myself when i used to buy/freshen up/sell on years ago. Been stung a couple of times but overall, there is money to be made and nice cars to be bought.