Madigan townland help, please.

I am asking for help with your local knowledge to make sure I have my Madigan’s all from the one family.

(1) John Madigan, Knockpatrick (Griffiths) was the father of an illegitimate son (2) James. James’ (2) mother was Margaret Enright.

(2) James was baptised on 28 Jan 1835 (NLI film 02418-01, page 128).

(2) James Madigan married (3) Mariam Guinane of Knockpatrick on 4 Feb 1856 (NLI film 02418-02, page 109.)

(3) Mariam Guinane was baptised on 9 Apr 1829, (NLI film, Shanagolden, 02418-01, page 64).

Their five children were –

(4) Thomas baptised 16 Dec 1856 Mt David, (NLI film 02418-04, page 99)

(5) Patrick baptised 18 Aug 1858, (NLI film Shanagolden, 02418-04, page 107)

(6) John Patrick baptised 12 Oct 1859, (NLI 02418-04, page 112)

(7) Mariam baptised 4 Jan 1862, (NLI film 02418-04, page 121)

(8) James Joseph baptised 11 May 1864, (NLI 02419-04, page 10).

Thomas (4), John (6), Mariam (7) and James (8) all migrated to Victoria, Australia.

I have a birth certificate for the Registrar’s District of Shanagolden for James (8) showing he was born on 10 May 1864 at Knocknasup, which was also his father James (2) address.

Irish Birth, Death and Marriage records show that –

James (2) died on 6 Nov 1903 and his address was Demesne.

Mariam (3) died on 25 Nov 1905 with the address of Demesne

Patrick (5) died 28 May 1933 and his address was Demesne.

In 1930, James (8) returned to Ireland holidaying and arranged a headstone on his parent’s grave at Knockpatrick Cemetery. The headstone included details of his father, James (2) name, after which was Mount David. Below, his wife, Mary (3) and Patrick (5) were named with details of their deaths.

On a couple of official forms in Australia, John (6) and James (8) have indicated that they were born at Shanagolden.

My questions are,

Does anyone know the townlands of Knocknasup and Demesne as I cannot find them?

Are Knockpatrick, Mount David, Knocknasup and Demesne all at Shanagolden?

Are they the one place?

Did one or more have a name change by officials, therefore changing a person’s address?

Are they so close that a person could use one or more as their address?

Or, after 20 years of research (not just Madigan’s) have I managed to inquire into a few different families???