The group is owned by Labour Party supporter Andrew Smillie, 60. Mr Smillie donated £1200 to the party in the year to March 31, as well as £2250 to charities.
The accounts show turnover rose by 16% to £6.57 million, with a direct impact on the bottom line, where pre-tax profit jumped from £149,621 to £460,973.
Writing in the report, the directors said gross profit rose by 27% and the advance was down to the company's "long-established and reliable reputation together with the consistent hard work by the company as a whole". They are "confident it will continue to trade profitably during these difficult times".
The group, based in Glenpark Street, and operating across Scotland, employs "more than 100", according to its website, though the accounts record the average number of monthly employees last year as 57, down from 59.
Its capital expenditure was constant at around £193,000, and it ended the year with net cash up 25% at £1.14m.