It's all very well when a scanning bureau is confronted by a "virgin" customer - one who has never dipped their toes into the murky waters of digitisation. But the chances are this is the second or third time around for them, and the old data is indexed in a weird and wonderful fashion. Standard answer from a bureau is, let's start from here and keep your old stuff as it is, which means that to find a document, a customer has two or more places to look in.
This is not Merlin's answer - we have wide experience of taking old data and transforming it to DocuStor-friendly format so that all archives are in the same place and found in the same way. This is not always a straightforward business:
As an example, a large multinational company had its HR records scanned into an old system that was nothing more than an old computer-aided microfilm system, with the microfilm frames replaced by single-frame TIFF images. The indexing system simply went to the first image for the required document and the user would then have to call up each subsequent image in turn until they found what they wanted. By a clever bit of programming, Merlin was able to combine images for each document into a single PDF and upload it and the transformed metadata to DocuStor, so as to be compatible with the new material Merlin was scanning for them - also to run everything through an OCR process to allow for content searching, which would have been more successful had the quality of the original scanning been up to that provided by Merlin.