I still down know what the problem is. You are talking about probable causes. All I know is that you downloaded one of MadMike's latest repaints which is based on the latest SW1200 update from Britkits. They work fine on my machine, so I am interested in know what issues you are having.
But let me try and guess. If you are having issues with older repaints while you are using the updated model, then yes, the texture maps have changed and you will see some strange results (missing textures, paint out of place, etc). If these are repaints that MadMike had done, then there is a good chance that he will update them. I also know that he has his eyes on some new repaints as well, so just hold on tight.
If the repaint was done by someone else, I cannot say if it will be redone for the new SW1200 model. You may have to contact the author of the repaint directly to find out.