photo_genie, the best person to answer any questions you have about the S3010 is Mark Tonkovich. He is also a member of this forum and works for Heidelberg. You can trace his ancestry in the company back to the Hell Graphic Systems days.
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Be sure to determine from the current S3010 owner what software revision is installed. A Linotype-Hell-Heidelberg software revision below 11 is pretty bad news. There are several add-on software packages as well. Heidelberg discontinued it's scanner product line a few years back and probably their service and support for legacy models as well.
After you know what's installed on the S3010 you could contact Mark and find out what kind of support (if any) exists for the S3010 (hardware and software). Mark has been around the business a long time and should be able to help you determine if the S3010 is worth your while or even suits your needs. I retired in 2001 and therefore cannot help much with more current concerns.
I was an Instructor with Linotype-Hell and delivered lots of training on the S3010 and the subsequent models S3800, S3500, S3700 and S3900. During it's hay-day, I always felt comfortable that Linotype-Hell made the best drum scanners available.
You'll also need some training, hopefully provided by the S3010s current owner(Linotype-Hell charged $1500.00 a day for my services back in the mid 1990s).
The S3010 is the oldest model in the line. It sported a variable aperture, whereas the newer models used an aperture wheel with only a fixed number of apertures. The S3010 looks a little different than the newer models, It is also mechanically and electrically different. Being that the S3010 is about 20 years old, spare parts and service cannot be overlooked, along with a through test drive.
Good luck to you.