Simon Glancey has submitted the following:

The Dundee Courier and Advertiser Wednesday, 13/09/1944 carried the following announcement of F/O Lunan's death:

LUNAN – Died in England on Sept. 10, 1944, as the result of gunshot wounds received on active service, Flying Officer William R. Lunan, beloved younger son of Mr. and Mrs. J. Lunan, of Morrison St., Kirriemuir. Deeply mourned. Funeral to Kirriemuir Cemetery on Friday 15th, at 2.30 p.m.

The Berwick Advertiser Thursday, 14/09/1944 also reported his death:

DIED AFTER AIR OPERATION
Mr and Mrs J. Lunan, “Lindisfarne,” Main Street, Tweedmouth, received sad news from the Air Ministry recently stating that their youngest son, F/O W. R. Lunan, R.A.F., had died following an air operation, in which he was wounded. He was 22 years of age.

Flying Officer Lunan joined the R.A.F. over three years ago, and prior to that he was attending Dundee University. A native of Kirriemuir, he is being buried there. Another son, George, is serving in the Dental Corps in Africa.

F/O Lunan was serving as a navigator on de Havilland Mosquitoes with 239 Squadron, based at R.A.F. West Raynham, Norfolk.

The Squadron's O.R.B. (Operational Record Book) records the following tragic details in their entry for September 10th, 1944:

A tragedy marked a perfect afternoon, when F/O W. R. LUNAN was found to have been shot by his own hand, shortly after lunch. An inquest will discover the full details but preliminary inquiries indicate suicide.

The Berwick Advertiser reported the news of the inquest, Thursday 28/09/1944:
Letters Not Read At Inquest
The contents of two letters left by Flying Officer William Robb Lunan, R.A.F., aged 22, of Lindisfarne, Main Street, Tweedmouth, who was found shot in his room at an East Anglian R.A.F. station, were not disclosed at the East Anglian inquest. The letters were addressed to Flying Officer Lunan’s mother.

The Coroner, Mr. W. J. Barton, recorded a verdict that the airman “shot himself with a revolver while the balance of his mind was disturbed.”

The same newspaper Thursday, 21/09/1944 carried this tribute to F/O Lunan:
ST. AIDAN’S CHURCH
The autumn Sacrament of the Lord’s Supper was observed at St. Aidan’s Presbyterian Church on Sunday evening, the Rev. R. Marshall Smart, M.A., Interim Moderator, officiating. In the course of the service Mr. Smart paid tribute to the late Flying Officer William Lunan, a member of St. Aidan’s, and who, on his leaves had been especially helpful and happy with the Sunday School children.

William Robb Lunan is remembered in Berwick on B25.43

Family headstone at Kirriemuir
The CWGC entry for Flying Officer Lunan