WW1- Great War Mugshots

[43rdRecceReg]

When my Uncle (Mother's brother) died in Glasgow, a couple of years ago, He left be a tin of family photos (and nothing else, the mean bastard!) Some pics date back to Victorian times. However, there are several photos of WW1 soldiers there, and I wondered if anyone could identify the units. One is clearly from the RAMC ('Run away matron's coming"!), as he's a medic, and he's also carrying an unusual amount of lard for those days. Three are carrying swagger sticks, and in the third, one is wearing a Tam O'Shanter (AKA 'Balmoral Bonnet'). They are all scots; but could one have been a tanker!? Oooh..