Old DWG putting in AutoCAD-Layer-Structure and perhaps more

I have an older DWG-drawing of an medical practise I consult and plan. The old plan is nearly all in one layer. This must be devided in separete layers to re-do a practise planning.
I need about 10 -15 layers. regular ones.
This has to be done a.s.a.p.

If possible we would need you to continue some new drawing in this plan. Therefore we will send handsketches which has to be implementated into the plans. But this is not part of this job, will continue...just an pre-information.

Prefer AutoCAD-Level. 2D at the moment.

We would prefer someone from the european area, so in case we find a good way for future works, we hope in a good communication. English is MUST, German would be fine.

Just, who we are:
We are a small engineer office with architectural service based near Regensburg Germany (south of Germany, between Munich and Nuremberg). One of our special fields ist "medical facilities", another special residential homes and sometimes fire-protection plans.

We look for someone for a longer relation in work.