Garmin 4010 £550
Garmin GPSMAP 4010 for sale
Was fitted indoors so never exposed to the weather, hence why it is in perfect condition, no marks, scratches etc.
This model is still current, cheapest I could find in the UK was £1250 so for £550 Ono this would be a bargain.
Comes with a gimbal mount and a power cable only but I have a box full of garmin spares, cables etc and would be happy to help with any extras you may need for your particular install.