Hello Dave,
I have gone through the images and the floor plan. However, I was not able to open the .skp file as I have a older version of Sketch Up. Would be helpful if it can be in version 8.
I am a qualified Industrial Designer with Mechanical Engineering background. I have around 15 years of professional experience working in the Automotive sector in the areas of Graphics, Interiors and managing projects from Concept to Proto build. Recently I have started off as Freelancer and doing projects in Packaging, Graphics , Modelling and Home Interiors. I could provide my work samples on request.
Coming to your requirement :
1. Clean it up a bit - Does this mean refining the overall shape of the model. Refining the boxi-ness. Please correct me if I am wrong.
2. Design revisions. If you have a new brief, I can come up with a concept. Or is it open to any ideas? Or do you need new floor plan?
3. Photo-realisitc renderings : I am not into renderings as I cannot provide at this budget. Rendering involves a numerous iterations with post-processing.
What I can do :
1. I can make sketches, provide a new concept based on your design brief ( as the case may be).
2. I can build up the sketch up model with interiors and detailing to dimensions.
3. I can populate it with necessary stock items and apply materials and shaders to make it appear realistic and the model is render-ready.
Please let me know if I am falling in your line of expectation, so that I can go to the next step.