Something of a long shot, but.

[shadowwind2112]

This might be a bit of a long shot but is there anything that links the following,


David Thomas
B:abt 1906 Llanfair, Merionethshire, Wales

Aelwen Thomas
B:24 Mar 1932 Blaenau Ffestiniog, Merionethshire, Wales

D:Mar 2006 Bangor, North Wales

Clara Ruth Williams
B:28 Mar 1922 Merthyr Tydfil, Wales

D:11 Jun 2009

Sidney Bright Williams
B:24 NOV 1887 Swansea, Glamorgan, Wales

and the following

William Williams
B:12 Oct 1873 Llangwn, Denbighshire, Wales

D:20 Mar 1945 Merioneth East, Merionethshire, Wales


Margaret Dorothy Thomas
B:23 Apr 1904 Gwyddelwern, Merionethshire, Wales

D:12 May 1998 Gwyddelwern, Merionethshire, Wales

Anything at all that might link them together.

[Annette7]

Indeed a long shot with those surnames!

However, there was no Aelwen Thomas born in 1932 but I think she was the Aelwen Pierce (birth June qtr.1932 Bangor), who married a Griffith J. Thomas Sept.1949 Bangor and that she is the Aelwen Thomas who died 2006 Bangor.

Annette

[mckha489]

Sidney Bright Williams.    Actually born 1883.

WILLIAMS, SYDNEY  BRIGHT     BRIGHT 
GRO Reference: 1883  D Quarter in SWANSEA  Volume 11A  Page 713

Probate in 1955 is to Clara Ruth Williams widow

marriage?

Marriages Jun 1952   (>99%)

WILLIAMS    Clara R    WILLIAMS    Swansea    8b   981   
WILLIAMS    Sidney B    WILLIAMS    Swansea    8b   981

His first marriage was to Rose REES in 1904
his father Henry, mariner.
in 1891 he (Henry) is a DockGate man. 

[mckha489]

This is as far as I can go. Can't link them all together but do have some connections.

William Williams was married to Sarah Catherine ROBERTS

https://www.familysearch.org/ark:/61903/1:1:X7J8-MPR

One of their sons was Gwilym he married Margaret D Thomas

Marriages Jun 1927 
Thomas    Margaret D    Williams    Corwen    11b   688    
Williams    Gwilym    Thomas    Corwen    11b   688

think this is her birth
THOMAS, MARGARET  DOROTHY   mmn ROBERTS
GRO Reference: 1904  J Quarter in CORWEN  Volume 11B  Page 359

so suspect she is somehow related to Sarah Catherine. Niece/cousin

There are trees with options but it's all a bit messy with Williams Thomas and Roberts all over the place. and I think some second marriages to people with the same names!

However this might be Margaret and siblings? with one of them a candidate for David at the top of your list

https://www.familysearch.org/ark:/61903/1:1:X7J8-SF5


So. Margaret is the daughter in law of William Williams, and also probably a niece (related anyway) of his wife. While David Thomas is her brother.

These all have very nice graves  eg. https://www.findagrave.com/memorial/192540679/gwilym-williams



I can’t figure out where Aelwen Thomas’s husband comes into it.  Think he could be this birth but not positive.

THOMAS, GRIFFITH JOHN.    mmn OWEN. (Owen added from freeBMD.  Not showing on GRO index)
GRO Reference 1928 J Quarter in BANGOR Volume 11B Page 665


Sidney Bright William’s father Henry was born in Ilfracombe, Devon abt 1849
. 
Henry had a son William Henry Williams, but he is too young to be William Williams b 1873.

Can’t see a brother of Henry that might fit either.

[shadowwind2112]

Indeed a long shot with those surnames!

However, there was no Aelwen Thomas born in 1932 but I think she was the Aelwen Pierce (birth June qtr.1932 Bangor), who married a Griffith J. Thomas Sept.1949 Bangor and that she is the Aelwen Thomas who died 2006 Bangor.

Annette

She was born in 1933

[mckha489]

Indeed a long shot with those surnames!

However, there was no Aelwen Thomas born in 1932 but I think she was the Aelwen Pierce (birth June qtr.1932 Bangor), who married a Griffith J. Thomas Sept.1949 Bangor and that she is the Aelwen Thomas who died 2006 Bangor.

Annette

She was born in 1933

In that case you will have seen the marriage in 1966.   I won’t post incase the husband is still alive, but his name strongly suggests a link to Sidney in your opening post.

But you can find on FreeBMD