His RAF record is the key to sorting him out. The date of birth seems to be correct on it. He was born in Somerset, but later claims to have been born in Canada (same name, same date) presumably to get residence in New York more easily.
1892 Jul 26. Born Chard Somerset (Stanley James Robert Mitchell)
1901 census at Hinton St George, Somerset.
1910 May 27 Leaves UK for New York (uncertain)
1911 to 1914 Working as a Civil Engineer in SPR Company, Chicago
His RAF record indicates he joined ASC in MT before moving to RAF
1917 Jun 18 Officer Cadet in RAF. Posted 10 CW at Denham
1917 Aug 10. Posted SMA at Oxford
1917 Sep 29 Posted CFS Hendon
1917 Nov 8 Posted School of Instruction Hendon
1917 Sep 17. The undermentioned Cadets to be temp. 2nd Lts. (on prob.) :General List (R.F.C.).- Stanley James Mitchell
1918 Jan 31 Posted 89 Squadron at Hailey
1919 Mar 12. The undermentioned are transferred to the unempld. list: — 2nd Lt. S. J. Mitchell.
1920 Aug 10 Joined ADRIC with service no 187. Posted B Coy in Tipperary, Section Leader and he must be i/c Transport for Coy
1920 Jan 2. Wounded at Ballineen. The IRA do not claim to have opened fire. It may have been a shot fired by another Auxiliary
WS812 states that the group ...struck for Shanaway. The four were Dan Hogan, John Ahern, Jack Nyhan and John Nyhan (second cousins). We hadn't gone a half mile when the first lorry of two with Auxiliaries nearly ran into us. We heard the grinding as they changed into lower gear to climb the hill quite near my house. Only for the sound we were caught, but we got over the ditch and across another one that ran away from the road. Two of the men with rifles lay on top of it with their weapons trained on the two lorries as they each passed, sliding over the top of the ditch and down on the other side and so away. The two lorries went on and spotting a man near the back of his house the Auxiliaries opened fire on him. He ran and they sprang from the lorries and spread out through the fields. They didn't hit him but they shot an old man further on and then put him on a shutter and had him brought to hospital. After- wards he got about £1,500 compensation. In the meantime we reached Shanaway and found Liam Deasy and Tom Barry there. We weren't well settled in when along came the same two lorries of Auxiliaries. They belonged to 'K' Company in Dunmanway way and had made the round and caught up with us. We got out the back and up the hill, though Barry was all for opening fire on them. He was dissuaded as seven of us would hardly have been a match for them. They raided the house and went away again. This happened about 2 o'clock and between then and 5 o'cloc1 they came again twice and raided O'Neills' each time. It could hardly have been doubted but some spotter had seen Liam and Barry coming there earlier and sent in the information to Dunmanway
1921 Apr 19 Awarded £1200 compensation for injuries. He appears to have been with K Coy at this point. In fact a platoon of B Coy was hived off and became part of K Coy
Fined 7 days pay by Commandant
1921 Sep 8. Posted to Depot Coy. Promoted DI2. A note about one months probation for whatever this job is, but difficult to read. It looks like "Appointed DTO on one month's probation" and confirmed on 3 Oct 1921. I assume this is a Division Transport Officer
1922 Feb 17. Discharged on demobilisation of ADRIC
1922 Mar 30. Joined British Gendarmerie section of Palestine Police as a Lieutenant.
1922 May 9. Resigned from British Gendarmerie
1942 USA Draft Registration card. Gives his date of birth but puts it in in Montreal. He is unemployed and living in New York
1966 Died in New York with correct date of birth