Hi tpb, Sorry you haven't received any response to your thread.
Can I ask if you know where the number 65003 came from? Assuming it is correct, it doesn't lead to any medal rolls or MIC entries which in turn suggests that he didn't serve abroad. But the picture may not be that simple.
Since he was born in 1899 I wouldn't have expected him to have been able to join up or be called up before 1917, assuming he didn't lie about his age. As you may know there was a large change to the numbering system used for the Territorial Force soldiers in 1917. Prior to around Easter 1917, all TF soldiers were allocated numbers according to the separate schemes in use in their respective regiments, but, in theory at least, no number above 49,990 was supposed to have been used. In 1917 the new system allocated blocks of numbers to different TF Regiments and Corps. These numbers were unique, ie no two soldiers could have the same number. Most new TF numbers were six digits in length - this certainly applied to all TF infantry. However lower 5 digit blocks of numbers were issued, mainly to the Yeomanry but this did not include the series 60000-70001, which appear to have been reserved. As far as I can tell no TF unit had numbers in that range.
Turning to the Regular Army which had a different system that wasn't altered until 1920, the block 64662-65363 had been allocated to the Royal Garrison Artillery Depot at Plymouth (No 3 Depot), but significantly this was for the period Nov 1915 – Mar 1916. Since this was before Robert reached 18 and therefore should not yet have been enlisted, I would doubt that that is how he got the number 65003.
Which leads back to my original question about the source of the number. If a digit (or indeed a pre-nominal letter) is missing, we have an altogether different search on our hands.
The final possibility is that he was, somehow, somewhere, issued the number 65003 on joining, but this was fairly rapidly replaced with a new 6 digit TF number, and it is that new number we should be looking for him with. Not all number changes were recorded in the medal rolls and MICs, particularly where soldiers were transferred out of their initial regiment to, for instance, a different corps altogether, eg from 5th Loamshires to the Labour Corps.
Have you tried checking the 1918 absentee voters registers? I am not aware how widely available such registers are in Scotland. Just to add that, although he wouldn't have been 21 (the normal minimum voting age for men) until 1920, section 5(4) of the
Representation of the People Act 1918 extended the franchise to those who reached the age of 19 while serving:
(4) A male naval or military voter who has served or here after serves in or in connection with the present war shall, notwithstanding anything in this or any other Act, be entitled to be registered as a parliamentary elector if that voter at the commencement of service had attained, or during service attains, the age of nineteen years, and is otherwise qualified.