1918 Jul 4. WO 364 records on Ancestry show that S/50177 and S/50323 were both transferred to the 11th Cameron Highlanders on 4 July 1918, via Labour Coys. of their respective regiments (Yorkshire Regt & Royal West Surrey Regt). So it would appear that Ward S/50242 and Walsh S/50244 were also transferred on that date.
1920 Aug 13. Year of Disappearances p167 missing Cork. Also missing same day J Walsh, Cameron Highlanders S/50244. A body exhumed in 1927 would appear to be Walsh, so the probability would be that Ward was also killed and buried in a bog
The Year of the Disappearances in Appendix 1 gives in his list of "Pre-truce absentees from British Troops in Ireland, taken from Dept of Defence Papers MA A/07304
The Regimental Museum says I have been quite unable to trace either Walsh or Ward. Though I cannot be sure, the regimental numbers you quote for them are not Cameron Highlander numbers at all. I thought the numbers looked unfamiliar at first sight and have consulted a learned and detailed paper about Cameron numbers, from the earliest days up to beyond 1922 when 2nd Camerons left Ireland. There is no such series as S/50000. I then read through the Regimental Magazine issues from 1918 to 1922, looking at the Orderly Room notes for the 2nd Bn and for the Depot to see if I could find any S/50000 soldiers at all or any J Walsh or J Ward with any number. There was no such soldier as far as I could see but I accept that this is not a definitive answer.
Graeme Marfleet emailed me. The Army numbers shown are impossible for the year 1920. The numbers must be 7 digits or less. No British soldier had an 8-digit Army number until about 1942. If they were serving in the Camerons when the entire Army was renumbered in August 1920 then their numbers would start with 292, as these do. My guess is that the actual numbers are 2923714 Walsh and 2923713 Ward. If they both transferred into the Camerons on the same day then I would expect their numbers to be sequential or very close to one another. 2. The Camerons certainly used numbers in the 50000 series during WW1. I don't know why that series was used but will certainly use these two unfortunate men as examples.