I do remember being rung up offering a draft on a Saturday morning (ETD 0500) to fly an empty B777 to Cardiff. Reporting time 0330.
The return to LHR was to be by a crew transit van.
The credit as it was longhaul was 3 hours.
At the time, after tax it was worth £140.
I did not comment to rosters on the financial gain but refused on the grounds that I had JCB driver turning up at 0900 to dig some foundations.
He finished at 1130 and took £150 for cash!!