Ramsgate to Ramsgate around the Isle of Thanet
D120A, me too, although a few years later, about 1956, in the infinitely superior Dragon Rapide.
However, after looking at my PMs, I see you know that, since we corresponded about it and you concluded it was probably 'WK. The fare had gone up to 7/6d (37 1/2 p) and still a fortune for my Dad, who paid for three of us.
First glider flight - Air Scouts T21B at Lasham in 1963. Mine was the last flight of the day and we found a thermal at the top of the launch and went up to the dizzying height of 2200', followed by loops on the way down!
First jet flight - Vampire T11 at Shawbury, 1968.
I realized recently that I've flown or paxed in more DH types than any other manufacturer's.