NOt sure, but he looks it.
Tim Mont, was only low 70’s too i heard?
MJ - 400/200m, was mid 70’s i think.
Also, re the tuna, depends on the quality and how is prepaired. I found freswater packed tuna is best for eating, but tuna in brine?? high in oil for sure, but is it the omega 3 or 6oil your looking for?? that im not sure? 
Another thing to look at, re weight gain.
your 71kg right now,
lets say 8% fat (no idea, lets just say)
that gives lean weight of 64.4kg.
now muscle they say is around 30% ish from that weight (bones, organs, etc.)
that gives muscle weight of approx 19.32kg.
if you gain 1kg in muscle weight, thats actaully around 5% gain in muscle mass!! A lot really.
RE the diet, i would try 1st, changing up the simple carbs to complex carbs, ie, brown rice, multigrain breads etc. See what happens in the next 4wks.
I would aim for that 1kg in Lean weight in that time. ie, 5% of muscle gain.
If your still not gaining, add some olive oil to your shakes, maybe a tablespoon to each. And buy some omega 3 tabs or even change your steak 3 x wk to a oily fish. This is on top of what you did the month leading to this point. ie, complex carbs and all them meals per day.
Gpp is approx 8wk right? possably you could or should really only gain around 2kg of lean weight, maybe only 1kg if its stubborn. That way, your not going to blow up like what kk mentions and when you start the strenght cycle is Spp1, your hopefully converting that extra 5-10% size to new power.
its been shown by bodybuilds on mass cycles, that anything more than a 1pound gain per wk is no longer muscle. But in the off season, they put on a lot of fat too. They eat anything and everything and gain many kgs in the off season, tis the best way to gain lean weight, but then they need to shred all that fat before comp. Not something you want to do as a sprinter. Here, you want lean weight gain, no fat gain. you dont want to be striping fat whilst at the same time, doing your Spp3, you’ll have no energy and run real poor. So, avoid eating like them. gain weight slowly and in the designated time frames ie, Gpp etc. After all, its 10wks and that could be 2.5kg?
If you did that every yr, in 4yrs, you would be 80kg, lean, very strong and powerfull. If you keep running that whole time, you will be a powerhouse for sure.
Gain 9kg in 6months, and im sure you’ll be like as KK says, big, but no power and slower.