I did mine over 2 years ago and I've been to sleep since so the details are fuzzy, as mentioned to do it as OE it's a dash out job so no go. I used metal reinforcing plates from the local hardware shop bent to fit the curvature of the binnacle and then fit to the dash panel underneath these were then 2 packed to the binnacle. To locate the plates to the dash panel I put the binnacle in place and marked the holes, drilled (carefully) the dash panel and used those screw in plasterboard/dry wall fixings (2 packed in again) the mounting screws then go into these.
I used the plates because the holes allow the 2 pack to squeeze thru and make a good bond with the binnacle but cleaning and keying is also important. 

Read More...