I've done all of this work before and is an incredible amount of time finesse and patience. Are you talking about every seal associated with all of the windows? This would also mean pulling windshield and rear window? There is always a chance that the windshield and rear window can stress crack in this process. What about the front seal on the rear side windows? If so then those rear windows would need to be removed. Are you also replacing the side vent window seals? If you are doing the vent seals then you are into removing the front door panels and removing the window felt, window glass, side window vent assembly. Window adjustments will have to be addressed. Also look at the wearable parts in your window regulators including the special star spring washers. You will have decisions to make.
The windshield and rear window would be cut out and lots of time to fully prep the body window channel to fully clean. There is really hard type of seam sealer in the body window channel. It might be cracked and or you could have some rust in the channel. Removing the seam sealer is a ****. If you go through all of this you will have to address the channel with appropriate corrosion protection and then apply seam sealer to replicate the original sealer that was applied to channel if needed. The lower chrome below the windshield and rear window will have to be removed.
With the windshield out there leaves room and opportunity to perform any work needed on your dash wood. That in itself is a whole nother kettle of fish.
Find someone who understands these cars to do the job. Shopping for expertise who will be fair with you is the way to go rather than the lowest price from a production shop.
If I quoted 40-60 hours to perform the job for every seal associated with the doors and windows I would be discounting the real time because I know I would have more time in it than just that. And that time might not include dealing with removal of failed seam sealer in the windshield and rear window channels and then corrosion protection and new sealer but I would think I would be being more then fair. Maybe a well versed Mercedes restoration shop can beat the above time. But remember its not about beating the clock in this job. It's about not breaking anything in the process and doing it right.
It is a must to use OEM seals for front and rear windows. The rest could be bought at Vintage Euro. see:
http://vintageeuroparts.com/w111.htmlThose on the forum that have done this kind of work I would think would agree with me on the time and expertise involved. When I got initially involved in a 220seb restoration I totally miscalculated the time and expenses to do the car correctly. To counter all of the diabolical work involved in restoring a W111 these cars are without question one of the best built automobiles of their era.