Evidence of residence in 1980s MN1 3(2)

I would really appreciate some advice. We are applying for citizenship for our 14 & 16 year old children. Their father is BC by descent with a BC otherwise than by descent parent. Their father lived in the UK for 3 years in the 1980s.

What evidence and/or documentation is required to accompany an application on MN1 under section 3(2)? Would a bank deposit book showing his address from that time be sufficient?

I would really appreciate some advice. We are applying for citizenship for our 14 & 16 year old children. Their father is BC by descent with a BC otherwise than by descent parent. Their father lived in the UK for 3 years in the 1980s.

Can you please tell me if the father is British by descent or British otherwise than by descent?

Father is British by descent (although born in the Colony of Kenya in 1957 but we've actually had this checked) and grandfather is British otherwise than by descent. Thanks.

Apart from having to prove that the father has lived continuously 3 years in the UK prior to birth of your children you might be asked to prove that he had no more than 270 days of absences in that period if you will be applying via route 3(2).

Thanks. Do you have any idea what sort of proof is required? The father lived in UK from 1979 to 1983 so evidence is in short supply now.