Fort William had BR design 350 hp. shunters from the summer of 1961 to sometime after 1974. (The source is Shed by Shed, Volumes 7 and 8, which - unusually - only give the departure date of the last one (08 718) as ‘between 6/74 and 8/81’, although Vol. 7 does give it as there in 12/74.)
12/74 would probably (roughly) align with the closure of the original loco shed - the new station opened in June 75 and the old shed site had already been cleared to release the and.
08s did still appear from time to time.
The Paper Mill purchased an 08 to replace it's industrial shunter, still retaining BR blue and number 08077. From time to time it would visit FW shed for any works beyond the capabilities of the Mill's own fitter(s), and if out of service for a spell they would hire an 08 from BR.
The 'new' shed was (presumably still is) a fairly modest affair, a single road with a pit and accommodating one loco, and staffing in the late 70s was one fitter on each of two shifts hence maintenance was not planned there although it could be done in an emergency by adjusting the shifts of the fitters to have both there.
Also, the Aluminium Works used to receive shipments of 'Petroleum Coke' for use in the smelting process, perhaps twice a year. 'Shipment' meaning literally a full ship load docked at one of the East Coast ports - I think Grangemouth - which came north in MCV and MCO wagons, some on service freights, and some on 'Coke Specials'. At any one time there could be 30/40 plus wagons on site and they would hire an 08 to shunt wagons around the site.
08s were also used on local trip work from time to time in the early 80's - perhaps after such hires.
Straying slightly off topic, one of the coke specials came to spectacular grief between Tulloch and Roy Bridge - mercifully not in Monessie Gorge as a number of wagons went down the bank followed by the brake van. The Guard walked away with minor bumps and bruises!.