Was just reading post #91 when you replied. :-)

I do have a Garmin 590 to play with, yes. (Flashed to 595, but still shows the Garmin Logo)

I'd really like an HD logo on the HD one, so I guess it may be possible to use a modified one, if the existing one is incompatible with the 595 firmware?

I won't flash anything until I'm properly certain, so I may be back to ask for advice!