The London watch was "passed" after bidding went from £32,000 to £36,000 (estimate 40-50). So it appears that there was a reserve price set at 38 or 40.
The buyer's premium is 27% plus 20% VAT in the UK on that premium (total 32.4% for UK buyers) but their expert just confirmed to me that if they handle the export to a non-UK buyer, that tax would not be added. Of coure, import tax & duty will occur at the buyer's frontier.