Yes, I remember Coe running that leg. It doesn't seem that impressive on the face of it, but it should be put into context. It was run in what, April 84?
Coe hadn't run at all from July 83 to Jan 84 due to toxoplasmosis, and he had just joined Haringey, relocating from Sheffield to London, at the beginning of '84. He spent the first few months of the year "running up hills with teenage kids" in order to acquire a strength base required for the Olympics. Not exactly the perfect preparation to be in even his normal form in the spring!
He had never really run in these sort of road relays before in this country. Certainly a Coe of 79-81 would probably have run a bit faster.
I certainly don't think that Coe would have beaten Geb or Teg over 10km, and the 10 miles in 45 mins wouldn't have been subject to IAAF scrutiny or anything, but the point I was trying to make, is that he had a lot more natural endurance than people credit him with. To beat Coghlan & McCLoud over 4 miles on 800m training and run faster in the Vigevano 7.5km road race than Ovett (clearly he was capable of 28 mins for 10KM anytime of the season up to about 1986) by over 30 secs, is no mean feat. Had Coe trained specifically for 5000m and run the distance competitively, I'm sure he was capable of well under 13:10.
I personally feel that he underachieved a bit in the 800m and 1000m, taken into consideration the former record was run in early June (and practically solo). I think he underachieved a lot in the 1500m/mile. He ran the events too infrequently at his peak and was unlucky enough to have some really dire pacemaking. What he would have achieved had he not been so blighted in 82 & 83, when he should have been at a peak, who knows!? But certainly anyone who can run the last 100m in 12.5 (and 300m in 39.0) in a 3:32 (Zurich 84) or solo run a 3:31 (Stockholm 81) going through 400m in 52.4 and 800m in 1:49.1!! was capable of a lot faster than his 3:29.7 pb at the age of 30.