I found the medal card on the National Archives Documents Online (can be downloaded for £2.00). I didn't download it, but it gave me the service number. I've just re-checked for Tom (rather than Thomas) and found another for R Berks R, private No. 7400 who received all 3 medals and was discharged, but no pension record for him or service papers.
I checked the info below on Ancestry
WWI service records - these vary in length per person, but often shows: Parish, town, occupation, birth, height, description, agreement to serve etc.
WWI pension records - they contain the same basic info as in the service records, but also gives details of postings, reason for discharge, amount of pension received. Again the amount of info varies greatly per person.
Looking back at the photo, the baton looks like a riding crop as used by a cavalry regiment, so it may be a prop. But I think the braiding is regiment related.
Let me know the name of your other ancestor and I'll look for you.
Regards, Tipps