In an interview he gave not long ago, Coe stated that he routinely got up to 100 miles a week usually running twice a day. This included 15 mile long runs. He did not do this every week but he logged many weeks at 100 miles. This was directly from Coe. I think I will take him at his word.
Another thing with Coe is that he never logged his warm up or cool down mileage this would easily add another 20 miles a week to the total.
I have not read much on the other runners you mentioned so I wont comment,
I will say that if you look at the great milers of today and throughout the last 30 years almost all have logged high mileage. Heck even most elite 800 runners are logging 60+ weekly during base phase.