Sounds like something to this was done for BeOS/Zeta a few years back. Someone skinned BeOS onto Ubuntu. http://www.zevenos.com/
Personally me being a BeOS user it made using Linux much nicer and made me use Linux more. Was it perfect? No but this was done very well. I used this for many years up until issues I had with updating packages which most likely had nothing to so with the skinning. I'm sure some users will like having the Ambient/MUI skin on Linux and use Linux more but it is not Morphos in the end.
G5 2.0DP, MorphOS3.13