Find Living Relatives

Please can someone assist me, I am trying to find my half brother,John Joseph Scallan or Scallon, who I only found out about approx two months ago. He was born in the Women and Childrens Hospital, Harrow Road, London on the 23rd January 1928 to my mother Ellen Shiela Scallan.
I know that he was adopted away from our family, and I presume that his name would have been changed to that of his adopted family. I believe he married but I do not know when or to whom, and I also understand that he changed his name back to Scallan or Scallon when he married.
If he is still alive, God willing, he would now be in his 84th year. I have checked on Genes Reunited in the Marraige and Death records but could not find any conclusive evidence.
All the information I have at this moment in time has been furnished by "Hoopers" the International Probate Genealogists, following contact from them about another half brother.
I would be most grateful if anyone can help me on this one.
Thanking you in advance,
Regards,
John

pm received includes the information:

'As far as we know he changed his name before marriage, but we are not 100% sure.
I have John's birth certificate, he was born in 1928, at the Woman and children hospital in Harrow Road, Paddington, London.
We are not sure where he married, but we think it may have been in London. '

Did you use the 191 link that I gave you?

Ancestry gives marriages in Manchester, 1948, Manchester, 1949, Ealing, 1949, Liverpool, 1964, Barton, 1973, Congleton, 1981.
The Ealing marriage corresponds to a birth in 1918 for John J P Scallan.
There is a John J marriage in Paddington, but in 1942, so too soon.

Hi Patchem,
Thank you for getting back to me.
I have tried 192, as suggested, but it did not show any possible matches.
I have also tried the electoral lists, but again no possible matches.

Thanks again, I will keep trying, you never know I might strike lucky.

John