And remember, it isn't just the cabinet that needs sorting - there are the works to consider too. Look at that rust! This set has clearly spent a long time in damp conditions.
Restoring the chassis was a lot of work: much of it had to be rebuilt from the ground up because of the corrosion. Parts that would normally be expected to pass muster even in a set as old as this, were beyond repair because of the amount of damp damage they'd suffered.
I don't have before and after pictures of the chassis, but in terms of appearance you're not missing much: 'After' actually just looks like a somewhat cleaner version of 'before'. That's because given that this was already an expensive restoration, the owner was quite understandably unwilling to have the chassis completely stripped, derusted and refinished as well.