Regimental numbers

[afb57]

I am researching my grandfather's service history and have found a discrepancy in his regimental number (assuming both records are for the same person). My grandfather was John William Barlow. His attestation 19 Jul 1922 • Sunderland.
Attestation : Regimental number : 2650368 Coldstream Guards 1921-1923 D series. Trade : Miner, Parish : Washington, Co. Durham. I have recently been researching his war service to find out more about his M.I.D. and what he did to be awarded this honour. I have found a record in the National Archives which appears to match family knowledge and placing him at Dunkirk. The regimental number, however, is slightly different. Same numbers but a reversal of last two digits
 J.W. Barlow 2650386 company serjeant major auxillary military pioneer corps 42 company British Expeditionary Force 1939-40 award.
 I have just sent off for his death cert. in order to request his service records which, hopefully, may clarify this but also wondered how much detail the records may contain about what he did to get the MID. The National Archive record has no individual detail other than placing him at the location (along with others). He was a captain by the time he left the army.
I would be very grateful for any help with where to go next for any further information about his service. Like so many of his generation, he did not talk about it and I am keen to make a record for my grandchildren.
Thank you.

[ShaunJ]

Have you seen the articles about the award in the Skegness Standard of 8 January 1941 (page 2) and the Lincolnshire Standard and Boston Guardian of 11 January 1941 (page 5) ?  "Gallant Spalding Man"

Formerly in the Coldstream Guards, married to Miss A B Stacey.

[afb57]

Thank you Shaun.
This is definitely my relative and I had not seen these articles before.