Gaunblur - what's the trick?

[IndioBlack]

I have the Memphis Belle B-17f add-on, but it appears to carry it's own specific gauges, so using gaunblur has no effect on this particular aircraft.
How do I unblur the B-17 gauges? Do I need special tools?
I'm assuming the Mathias who posts here regularly is the author of gaunblur.