If you look on the A2A website under 'Ipswich Group Hospital(s) management committee records' it gives a list of those held by Suffolk Record Office, Ipswich branch. It may be helpful, if only to exclude them from your search!
I was born pre NHS at Ipswich Maternity Home, Wingfield Street, as was my daughter several yrs later under the NHS. I believe this is the Nursing Home to which Mary refers to as being in the same grounds as 7 Lower Brook St.
In 1978 when I worked in Lower Brook St, number 7 was occupied by a firm of solicitors called 'Josslyns'.
Hephzibah