Haswell 21" iMac, unable to deploy images to machine

Simple problem causing a massive headache here.

Background is that we purchased many Ivy Bridge iMacs and built an image based on 10.8.4 with many adjustments which deploys on all our machines without problem.

Now we have 4 iMacs with Haswell chipsets and I am unable to get these images to boot on the new iMacs.

I have tried installing the 10.8.5 combo updater at the image running on a Mac Mini (Ivy Bridge) then target disk mode the drive from the iMac. I receive a "no entry sign - a circle with a line through it - instead of the apple logo.

We are using monolithic imaging so if I can't get these images to be useable on Haswell iMacs then I have a load of work to do and need to stop wasting time trying to get it working this way.

My understanding was that the drivers for Haswell are not included in the normal version of 10.8.4 so updating with the combo updater to 10.8.5 is way to go but do I need to completely rebuild my image at this point because I cannot get the iMac to boot it and therefore I can't update it using the iMac except using target disk mode and updating it as an alternate disk (ie not the current boot drive).

I have read the article here:-

http://support.apple.com/kb/HT5599

This suggests using the latest hardware to create your images but what about if your image won't boot on the latest hardware, do you have to start again? Going Casper this year but not yet so there is light at the end of the tunnel using modular imaging but right now this is a bit of a nightmare.