yes please bring back Historic. If there is a cost to you then work up a model to make some money - but I guess you need to know how to cost based on how many potential users. You will bring ALOT of interest to your site if you gave a free trial for historic for say a week, and I am sure the genuine users of this data will not be able to stand not having it after seeing it again and would buy it.
There will be significant commercial interest - but please don't forget the normal people also :)