Jan,
Would you like to upload the image to the site so that we can have a look at the image for you?
I had another look at the medal roll and see there is a single page for the 3rd Scots Guards, listing 6 names. There may be other pages as I haven't been through the whole roll.
The 6 names are:
Barclay, WM
Burgess, HT
Lynn, R
Perks, T
Rickey, J
Tuckley, J
The medals were issues 28 Oct 1903.
A few pages later on in the roll, under the title of the 2nd Battalion, the 6 men are listed again (plus an unfortunate Pte Wood who was discharged as "Incorrigible and worthless" and thereby forfeited his medal).
This supplementary roll shows entitlement for T Perks of the clasps Transvaal, South Africa 1901 and South Africa 1902. This means he went to SA in late 1900 or 1901 and did not spent more than 18 months in the country as he was not entitled to the KSA.
It is not unusual for the extra clasps to be separated from the medal itself, as in this case. Sometimes you see them attached to the ribbon, sometimes roughly attached to the other clasps and often as missing altogether.
There is a note saying that the 6 men were part of the corps of signallers.
So my surmise would be that these men from the 3rd Battalion were sent to SA in 1901 to join the 2nd Battalion and either replace missing/injured signallers in the battalion or, more likely, to augment their signalling capability.
Best wishes
David