108s were regular visitors to the coast line via Hartlepool (I grew up living beside the line in Billingham!). They'd generally be covering for 143s with gearbox faults but I think there was a booked daily turn through from Carlisle to 'Boro. They lasted longer than the 101s and there was even the green celebrity one kicking round at the end of the 80s/ early 90s.
Because of the gearbox issues loco-hauled sets regularly appeared- I had 31196, 31264, 31278, 31283 and 31285 on Darlington to Hartlepool services. The coast services were also regularly loco hauled- a few rarities appeared including 37501, 45128, 47053 and 47522. They were all nearly always formed of 3 coach sets, mainly blue & grey mk1s.
There was an influx of totally knackered ex South Wales units in '88 too but they were only there 'till early '89 when the 142's and 143's illnesses were cured.
Also remember (I think it was 1991) 158714 toured every line in the area (and most of the UK!) fitted with little cameras at each end checking clearances at the stations!
Thornaby locos give a massive livery choice- from 37501 in BS blue, through 47305 in br blue with a yellow stripe to 37358 in freightliner blue! Also dealt with cement, speedlink, coal, oil, hydrocyanic acid(!), steel, potash so would heartily recommend it to model!!! Especially looking at the Bachmann 37514...
Good luck!!!