Are all 6 series dashboards the same? What about the ducting? Specifically, can I replace my 81 dash with one from an 85? Can I adapt the AC evaporator box as long as I'm willing to deal with the electricals? I have a complete 85 interior with a perfect dash and AC unit that I would love to use to replace the cracked dash and dated AC stuff in my 81 Euro. Any input would be greatly appreciated.