Update:
Quite a lot has been going on with this build to mend and correct, with a lot of help and input from the Tonymacx86 forums.
1) Wake and audio after sleep proved not to be so straight forward after all. With the original TP-Link wireless card and Belkin BT USB everything worked as it should with CodeCommander.kext installed. Sleeping slept and when woken audio was operational again. Changing to a genuine Apple wifi-BT combo card in a mini-PCI-e adaptor saw an immediate bounce awake from sleep and no audio any more. Pinning down this problem has not been easy. Updating CodecCommander to the latest version has restored audio but the immediate wake issue seems to be USB related. Work is ongoing.
2) Continuity and Handoff, iMessage and Facetime all became operational once the Apple combo card was installed, however the system was telling fibs. Only Facetime was actually fully working.
Sensibly, and in hindsight, the system had to seem more
real that it clearly was. Various serial numbers and code IDs need generating and tweaking to get everything working. The basic MultiBeast installation method does its job perfectly and is designed as a superb catch-all for the various hardware components we use but I'd been using Clover Configurator to modify things, along with various patches, trying to resolve the issues. This had clearly upset the system and if certain codes and IDs are no longer seen as genuine, things don't work. Corrections were needed such as MLB and SMUUID, the serial number had to be checked as a genuine one that matched the type of machine I was emulating.
The answers are all here on Tonymacx86, and for me the most concise and useful guide is by P1LGRIM here:
http://www.tonymacx86.com/threads/s...-ds3h-a-i3-4330-geforce-gt640-10-11-4.189452/
It is designed to get iMessage working but it also ensures Continuity and Handoff will work properly too. Once done you will need to sign in to iCloud again.
3) Be careful making system changes. I was keen to move from a MacPro3,1 system definition to iMac17,1 having a Skylake system and wanting to ensure I was Sierra-ready when the time came, figuring I'd iron out any problems now rather than later. This will change your serial number and once more iCloud will want a new sign-in. You can get around this by using your original serial number and pasting it into conflig.plist over the new one, however it will NOT match the new system type and thus scupper Continuity etc. so I went with the new one. However ...
All these changes meant my copy of Parallels Desktop VM needed re-activating, as did some other software that uses an activation scheme (too much like Windows and Office for my taste). This has the potential to cause problems if the software has an activation limit. You're going to have to contact the devs support team to have your limit re-set - or buy another license.
4) Hardware tweak. Use a desktop aerial for bluetooth. Being a metal case under a desk didn't seem to cause any wifi problems, but the router is only six feet away. Bluetooth was a different story. Find out which aerial lead is for BT - on the card adaptor I bought it is helpfully printed on the surface - and attach the external aerial to that. This will improve things no end.
This is the one I bought:
http://www.ebay.co.uk/itm/181818407485
Two leads, one to BT and the other a wifi. The extra wifi socket has a standard aerial attached.
So now everything works except: Wake from sleep and iTunes DRM video (affects most recent hackintoshes)