The first mention of the Merlin in my personal database of first flights is Hawker Hart K3036 on February 21, 1935, powered by a P.V.12 which was to all intents and purposes the forerunner of the Merlin. The next entry that relates to an actual Merlin is the Haweker Hurricane prototype K5083 on November 6, 1935 as so many have already stated. This was a 990 hp version Merlin “C” no. 11, so numbers 1 to 10 were very probably ground test engines. That would make the Hurricane definitely the first true Merlin-powered aircraft.

Another scan, this time from “The Encyclopaedia of British Military Aircraft” page 71 – the cockpit area seems to be silver like the rest of the plain parts of the fuselage.
If you are in Sweden you could borrow some books from my fairly extensive library. Come down (up?) to Göteborg one day! PM me to pursue that thought.

Sorry, just discovered that the .bmp option for this site is not very good! Here instead is a scan of the photo on that page.
Designed as a single-seat interceptor the Grebe II in the photo was designed to AM Spec. 37/23, powered by an AS Jaguar IV 14-cylinder radial. All wood construction with fabric covering, span 29 ft 4 in, length 20 ft 3 in, height 9 ft 3 in, wing area 254 sq ft.
Max speed 162 mph at sea level, climb to 20 000 ft in 24 min, service ceiling 23 500 ft, normal range approx 310 miles.
Armed with 2 fixed synchronised 0.303 Vickers Mk 1 machine guns, 600 rounds per gun.
4 prototypes, first flew May 1923. 108 Mk II fighters built, 21 Mk IIIDC trainers built. Served with 19, 25, 29, 32, 56 and 111 Sqns.

Here’s a 3-view from page 162 of my old standby “The British Fighter since 1912” which probably has all the info you want.

Page 95 of Putnam’s “The British Fighter since 1912” has a photo of the first production SE5, A4845 with the canopy.

Dayton 2003, the “wall of fire” was the follow-up to this attack