My recollection of Boro was that they actually were in The Kippax and they tried to storm The North Stand .
It was the season when the newly built North Stand had no seats installed (for one season only) and the new stand was taken over by City's more vociferous fans. So all away fans had to go in the now vacated Kippax Street stand.
And Jeff Winter is 100% right ,Boro did try to get into The North Stand, but were swiftly dealt with and soon ran back into The Kippax.
It was the season of the 3-3 derby game so that dates it to 1971-72 season.
I was born in 1956 and was 15 at the time.
So if Jeff Winter was born in 1955 he must have been 16 , assuming my maths is correct.