Hello Martin,
Welcome to Rootschat

You say perusal of the appropriate PRs - there are quite a few parishes in Ipswich our county town.
In case you are not sure of the parish, this is a list which might be of some help ~
IPSWICHAll Saints - PRs available from 1882-1900 on 9 fiche at the SRO and they are
available to purchase
Holy Trinity - PRs available from 1837 - 1900 on 20 fiche - as above -
St Clement - PRs available 1563 -1900 (registers 1710-1812 are only
available on a roll of film - other records are on 88 fiche) - as above -
St Helen - PRs are available from 1677 - 1900 on 32 ficher - as above -
St John - PRs are available 1880 -1900 on just 5 fiche - if you wish to
purchase, you need to obtain the permission of the present incumbent.
St Lawrence - PRs available from 1539 -1900 on 17 fiche - available to
purchase from the SRO
St Margaret - PRs are available from 1537 - 1900 (marriages 1563 -1669 are
available on 1 roll of film only) there are 93 fiche for this parish and
they can be purchased
St Mary at Stoke - PRs from 1669 - 1900 on 24 fiche (however, registers from
1563 - 1669 are only available on one roll of film) and they can be
purchased
St Mary at the Elms - PRs available from 1557 - 1900 on 24 fiche at the SRO
and they can be purchased
St Mary at the Quay - PRs on 25 fiche from 1559 - 1900 - as above
St Mary-le-Tower - PRs available from 1538 -1900 on 24 fiche - as above
St Matthew - PRs from 1559 -1900 on 77 fiche - if you wish to purchase you
will need to apply to the present incumbent for permission to buy
St Michael - PRs from 1881 - 1900 on just 5 fiche - can be purchased
St Nicholas - PRs available from 1539 - 1900 on 38 fiche at the SRO and they
can be purchased
St Peter - PRs from 1657 -1900 on 49 fiche and they can be purchased
St Stephen - PRs available from 1585 - 1900 and they can be purchased
You can purchase fiches of the PRs, you need only buy the years that you are
interested in - for example if you were looking in St Peter's you do not
need to buy all 49 fiche for that parish.
http://www.suffolk.gov.uk/LeisureAndCulture/LocalHistoryandHeritage/SuffolkRecordOffice/Some of the above churches were built in the Victorian time to cope with the
growing population of the county town. You will also see from the number of
fiche produced for the baptisms, banns, marriages and burials just how busy
(or indeed how quiet) a parish would have been.
You can check out these churches at
www.suffolkchurches.co.uk that way you can also locate where they are in relation to one another.
With best regards, SM ...