I too spent a very enjoyable hour and a half at the Royal Welsh Museum at Brecon earlier this year and was well impressed. Sadly I could not find the medals of my one Smethwickian who served in the SWB on display. He was 6119 Private Thomas Fallon who served in the 2nd Battalion in South Africa earning the QSA & KSA. In October 1902 he was transferred to the 1st Battalion and then spent best part of 5 years in India. He was discharged on 09/03/1910 having completed exactly 12 years of active service.
He was born in the Rotten Park area of Birmingham but by the time he attested for Militia Service with the Worcestershire Regiment aged 17 years 3 months in February 1899 the family were living in Smethwick. A month later, by when he had miraculously become 18 years 2 months old, he attested in Worcester for regular service in the SWB (don't ask me why the SWB). By the time of the 1911 Census he had returned to Smethwick where he was working as a "Brewers Drayman" and had a wife of one year's duration and a four year old son who, if he was the biological father, must have been conceived shortly after he arrived back in England from India. He was not a model soldier as he was court martialled in SA for "neglecting to obey a camp order" and did 25 days IHL, also whilst in India he twice forfeited his GC Badge & pay. By the time of the Great War Thomas & family were living on the Dudley Road which runs from the border of Smethwick to the centre of Birmingham. He enlisted very early in the Great War but his service seems to have had nothing to with any Welsh Regiment. He was not demobbed until 1920 and then appeared to evaporate but perhaps I have not looked hard enough, although I have a suspicion his son ended up MD of a major Smethwick Firm and was awarded the OBE in 1958.
Happy to email you all his paperwork plus my notes if you are interested.