Sorry to keep replying, but I've just realised something. Those receipts represent a very specific time in British history.
The fact that the phone number begins 0773 but the fax number begins 01773 shows that this dates from around when the renumbering was taking place.
Way back when the receipt was written, area codes (the first few digits) could be numbered anything, as long as it started with "0".
However, in the 90s, the shift towards all area codes beginning with "01" had started. In April 1995, any remaining numbers that were still "0" were changed to "01" overnight. So this receipt dates from when the shift had started but not finished.
Not helpful in terms of identifying the Orks, but hopefully a little interesting!