If drugs were being used by some nations under some kind of state sponsored programme during the 80's then you would expect both their male and female athletes to be competing at a similar level. The 800m lists do not show this at all. There are hardly any East Europeans in the men's list, and hardly any Brits or Western Europeans in the women's.
The general consensus at the time was that steroids, the ped of choice at the time, benefitted speed and power events. Almost all those caught in this era were throwers or sprinters. I cannot think of a single elite male mid distance guy from that time testing positive for steroids, and I think most elites from that time would tell you that it wasn't considered of much or any benefit for middle distance events. The only exception would be for women, whose physiological disadvantage compared to men would respond far more if steroids/testosterone were introduced, whatever the event, and give them a more 'male' appearance and a clear advantage over those not using.
It is clear that the Russians who were running 1:53-1:55 and 3:52-3:57 in 1980 were clearly on something, and we now have more recent events confirming a long systemic history of drug use in that country. At the same time we had the British and US women struggling to break 2:00 and 4:00. Surely if the western men were using steroids, then why not the women?
On the flip side, if the western guy milers were all doping, then why did the Russians and eastern Europeans have such a relatively poor record in those events. Indeed, they had the odd performance in a major champs, usually held behind the iron curtain, in which someone would run way above any level they'd shown before or usually showed again. Maybe they were experimenting with blood doping or something else but never quite felt they'd found the right formula to guarantee long term superiority.
It seems far more likely to me that those 'Communist' nations which considered sporting prowess to be an extension of the greatness and superiority of their political ideology, basically encouraged their male athletes in power events (throws and sprints) to dope and their women also. That would also explain why the German and Russian men generally stayed at the top in the sprints and throws. If everyone else in the West were doping to the same extent, then surely the East Europeans wouldn't have been able to stay on top for so long?
The likes of Walker, Scott, Coe, Ovett, etc, would have got involved in T&F in the 60's when it was amateur and there was little if any money to be made. There wasn't the huge monetary incentive to get involved, and there certainly wasn't the psychological incentive to 'cheat' for the honour of their nation and way of life, as there would have been installed in those youngsters with talent in the East.
One also has to realise that the middle distance guys would have been tested for the same things as the sprinters, women and other groups. Yet, how many can name an elite male middle distance athlete from the late 70's and early 80's who was caught? There were plenty of East European women middle distance girls caught, and many sprinters and throwers of both genders. If all were equally doping then that wouldn't be the case.
It should also be remembered that the UK were randomly testing their athletes (and catching them) out of competition from 1984, long before the IAAF introduced it for the World's elites in early 1989.
Blood doping was banned in 1985, with Coe doing a lot to bring this about. It seems strange therefore, that his best time in the longer, more aerobic 1500m, should come about a year later in 1986.
Indeed, in 1989, at the age of 32, and by then having been randomly tested out of season by UK athletics for several seasons and also by the IAAF that year, he was still able to run 1:43 low and come close to winning the World Cup gold over 1500m. It does not seem implausible that someone running such times clean, in an environment of such random out of competition and out of season testing, wouldn't have been capable of 1:41 high and sub 3:30 clean, a decade earlier when in his peak early 20's?
And the fact he could no longer show and maintain peak form week in week out in his 32nd year, but rather reach a few small patches of top form, is totally in keeping with the natural effects of ageing and gradual decline.
The overwhelming evidence we have about drug use in the decade leading up to 1983 and the introduction of professional prize money and sponsorship, is that it was far more prevalent in some countries; namely Communist east european ones where there was definitely a state involved system that had nothing to do with financial gain; and in some events; namely those which were considered beneficial to the use of muscle building steroids. There is little evidence any of the world's leading middle or distance guys were using steroids. There is only a small amount of evidence that some were using blood doping. As far as I'm aware, only a couple of Finnish and Italian distance runners have ever admitted to homologous blood doping. These were 5 and 10k men not half miler/milers.
IIRC, the Italians only dabbled with this from c. 1983, which for me is a bit of a watershed year. With the introduction of trust funds, legal sponsorship deals, prize money and the introduction of the Grand Prix a year or two later, there was for the first time, BIG money to be made if one was an Olympic champion or world record holder. As a result, I would not be surprised to see the percentage of athletes that used drugs increase after this juncture.