First could you clarify what class. C1 can drive a goods vehicle up to 7500kg GVW (with a trailer up to 750kg). Class One (in the old parlance) is now C+E and you can drive an articulated/wagon and drag vehicle over 7500kg.
https://www.gov.uk/driving-licence-categories
I don't know what the rates are in Scotland, but down here in the Midlands you would get around £10/hr as an agency C+E driver, plus time and a half for weekends etc.
If you didn't know about the licence changes (which happened over 10 years ago!), do you know that to keep your LGV (used to be HGV) licence, you must complete a Driver CPC by 9th Sept 2014? This involves attending 5 7hour courses (ie 35 hours in total) at a JAUPT approved centre before that date. More details here https://www.gov.uk/driver-certificate-of-professional-competence-cpc/overview