I used the same technique of re-naming and re-uvmapping for the shot looking into the building as I did on the external. The process was far quicker this time and has allowed me to simplify what was a rather complicated model. Unlike the external this one required a lot of re-modeling but thankfully practice means I'm getting much quicker at this. The new maps have been exported and will be completed this weekend ready for material experimentation and rendering next week. I feel like I am finally making progress but acutely aware of what is left to do.