Mercruiser Service - Oban area

[Duster]

We are based at a small boat yard south of Oban, the staff there are very kind and helpfull but more used to small diesel engines in yachts than sterndrive petrols.The nearest main dealers are 100 miles away.
Please can anyone recommend a mobile engineer in that area who would have the experiance to service/repair Mercruiser sterndrives?
Regards Mike