Try this global map of repair groups. The Amiga isn't a totally unique device, so people with enough experience of repairing electronics in general may be able to help you. I regularly attend Restart Project parties in London and I showed them a live version of Aeros. If these other groups are anything like as good as the Restart Project, then they should be able to help. I even met a repairer once who owns three Amiga A1200 computers!
http://www.therestartproject.org/global-map-of-repair-groups/
