Hi I am not sure if you have searched the 1901 Census but I found a Cyril Rees aged 7mths in 1901 born in Bridgend Glamorgan living in Oldcastle Glamorgan
Id Code for him is 19765814, other people listed with the same id are a:
John Rees Aged 8 born in Yorkshire Leeds living in Oldcastle Glamorgan
and also
William Rees age 39 born in Merthyr Tydfil Glamorgan living in Oldcastle Glamorgan his occupation is a teacher.
I have found this entry on the Free BMD site for Clyde:
Births Jun 1899
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Rees Clyde Cyril Bridgend 11a 825
It could be that your Clyde was known by his middle name.
I hope this helps you.
Regards Jen
