Just make sure you scale down ALL the measurements, not just the length. I tried to scale down just the length of a S&G once, and none of the panels fit together. Scaling down all the measurements will keep the proportions correct, and the panels should fit together.

Remember that scaling everything down may have some unintended results. The cockpit may not be wide enough for you at the new size. Also, the volume (L x W x H) will be reduced a lot, so you should consider this as well.

You could always make a model to practice scaling things down at a low cost.