I'm wondering if anyone could tell me in which unit Flying Officer Keith Campbell JOHANSON 414634, RNZAF was serving in 1942 before he was posted to 50 Sqn. I know he was posted there from 1660 HCU in December 1942.

The following was reported in the Newcastle Journal in early October 1942:

Twenty-eight year old Sergeant George Robinson, of 76, Severs Street, Middlesbrough, successfully fought a duel with Germany’s latest fighter, a F.W. 190, over the Bay of Biscay recently.
Robinson, a bookmaker’s clerk before the war, joined the R.A.F. as an aircraftman in 1940, but volunteered for flying duties a few months ago. He became an air gunner, and was posted to a Coastal Command Whitley Squadron specialising in attacking U-boats.
On his second trip into the Bay as rear gunner, he had a duel with a F.W. 190. The F.W made six attacks on the Whitley, but eventually retired with smoke pouring from its engine.
While the Whitley was being flown towards the Bay of Biscay by Pilot Officer K. C. Johanson, Hamilton, New Zealand, in search of U-boats, Robinson saw two F.W.’s ready to pounce.
“The first fighter came as close as 150 yards and did not open fire,” he said. “The front gunner gave a few bursts, and that was enough for the German pilot. He flew off.
“The second F.W. pilot was more determined. He climbed to a thousand feet above the Whitley, now at sea level and zig-zagging violently, and made five attacks. But his aim was bad. The bullets were flashing past me into the sea.”
On the sixth attack Robinson fired his gun so effectively that he hit the F.W.’s engine when about 300 feet away. The F.W. flung to one side, broke off the fight, and disappeared into cloud, with grey smoke pouring from the engine.

Robinson was still part of Johanson's crew when they were lost in Lancaster ED527 of 50 Sqn on February 5th 1943. I'd like to track down the Whitley's ID, so need the unit first.