The Slingsby T-67 was a design that was quite popular when I was younger.  They were aerobatic and were used for training by a number of establishments.  I didn’t think of it as a plane that got much traction outside the UK market but maybe they did okay.  Seeing one in the US was a bit of a surprise.  This example was taking off at Paine Field.  I wondered whether it was an ex-military example that had been sold to the civil market.  If anyone knows the background, do let me know.