I doubt this can be done, but I've flashed and tried the stock GingerBread, ZombieStomp and ApeX on my D2 R2D2. But I found that I was missing some of the R2D2 stuff and the only items that I truly liked was the new Blur Weather Widget and the Blur Social Networking Widget from 2.3. So I restored my 2.4.5 Starwars backup and cleared out the blur and extras I didn't want but I would very much like to have those 2 Blur apps. Silly I know. But is there a way to replace the 2.2 Blur versions of those apps with the gingerbread 2.3 Blur versions running the 2.2 (R2D2 2.4.5)?
And yes, I've tried just copying the required apk files into the system/app fold and changing the r/o to r/w. But when I did this, the apps/widgets didnt show up as if they were not installed.