he ran the last 1200 in his 3'33.1 in 2'46.6 & that included a slow lap of 59 or 60 in it
he only really kicked hard in last 300
that 2'46.6 is likely true finish as i've seen quoted 2'47.7 as his last 1200, but that virtually certainly is the time for bailey the leader at 300m - ryun's finish in 3'33.1 - ryun may have been ~ 8m behind bailey at 300m ( not on vid , but it can be surmised as he was long way behind at 100m & even more at 400m
http://www.britishpathe.com/video/jim-ryuns-world-record/query/jim+ryun
)
2'46.6 is 3'38.25 pace
now, obviously 1200m isn't 1500m, but i don't know how much drafting he got as he runs wide a lot in that vid & a short keino isn't going to provide much cover for a ~ 6'2 guy, & a 59 or 60s lap in that 1200 shows plenty of uneveness + main effort looked in last 300m
i really don't think that he wouda been much slower than extrapolated 3'28.25 at perfect, even pace for that - maybe 3'29.0 - 3'29.5
knock off 3.75s for dirt/synthetic at 1s/lap ->3'25.25- 3'25.75
( you can see the poor state of lane 1 in this ( not surprise as presumed highlight of meet, it wouda been one of last races on :
http://tinyurl.com/c6o8xye
))
then factor in that is was run in brutal 95F in smog capital of western world with worst air pollution & at very least you gotta knock 1s off that if run in 70f in nice, "clean" air of say oslo/stockholm/hengelo/etc
that gets you you 3'24
he is also quoted as having run a 47 aged 17y, obviously again dirt track, meaning he musta been good for 46 at 20y, his peak
that's into the 45s on a synthetic track
lines off fit i'd offer
46.0 with
3'26.0 ->1'41.37
3'25.0 ->1'41.09
3'24.0 ->1'40.81
45.5 with
3'26.0 ->1'40.89
3'25.0 ->1'40.61
3'24.0 ->1'40.33
45.0 with
3'26.0 ->1'40.42
3'25.0 ->1'40.14
3'24.0 ->1'39.86
that is why i reckon low-1'40 was fair value for him in that form