so my DP to HDMI cable just arrived. I connected it and still no acceleration. So, now getting frustrated I decided to revert back to the original config.plist you provided me with @Jake Lo and reinstated the DSDT.aml you provided me with to get my sounds working. I changed the audio to 3 and the graphics platform ID had a typo so corrected that to 0x0d220003. Rebooted and TADA, graphics are accelerated showing 1536mb. Thanks again for your help and patience Jake.
Much appreciated