This website did a piece on this auction titled.... "The 100 Most interesting sales at Las Vegas motorcycle auctions"
I didn't look for the 175 racer in the article, but the GTR is one of the chosen and is the 6th bike down the list.
https://newatlas.com/100-most-interesting-sales-2018-las-vegas-motorcycle-auctions/53141/"This was a bargain for someone. Until the early 1970s, globally renowned tire manufacturer Bridgestone also made a range of motorcycles which were of exceptional quality. This was the largest capacity motorcycle produced by Bridgestone, the 350 GTR, and it was produced in very limited quantities, believed to have been just 9,000 units.
Around that time, the other major motorcycle manufacturers made Bridgestone an offer it couldn't refuse: stop making motorcycles or we won't use your tires on our motorcycles.
Bridgestone complied, and this road going motorcycle, which was faster than the Yamaha 350cc Grand Prix roadster (see below) of the same period, was shelved. It was faster thanks to its use of disc valve induction and this bike was sold with just one previous owner plus full documentation including the original owners manual, and an original parts catalog."
EDIT: Ok, the racer is in there but a lot further down the list.