Old Master - modern puzzle

I wanted to do a fairly simple 250piece Wentworth puzzle - this one I bought s/h a while ago but had not done it.  This is a section of ‘The River Thames with St Paul’s Cathedral on Lord Mayor’s Day’ painted by Canaletto in 1747-48. The original painting is in the National Gallery in Prague. I find it interesting that after over 250 years, not only does the painting still exist, but also the Cathedral and the tradition of having a Lord Mayor’s Day in London. Not on the river like this, though.
 The most recent occasion that we had a river pageant like this was for the Queen’s Diamond Jubilee in 2012 - see extras (images from Wikipedia)