During the last two weeks we extract data from the similar Toshiba with a concentric scratch as well, all that time it reads steadily, but slowly -- approx. 2.5 GB/day. And that's 24/7 extraction.
I.e. the total time required could easily be up to a year, so consider what price would be reasonable for such job.
Also, according to our experience, directory structure could be lost and if the target data is database(-s) of some kind, then probably it's better to not start at all. For video chances aren't high as well.
But if the client needs photos, MS Word, Excel, PowerPoint, .PSD files, etc., then it's worth trying.
Doomer wrote:the top surface is actually H0 on those.
As for the head 0, if I recall correctly, it could vary for different models. I don't remember for this particular model, but suggest to rely on Doomer's info.
Generally the best way is just to check which head is which, although it's not critically important. Data can be extracted from Toshibas in similar condition, but as you see, it's a real PITA :)