Looking for a Joshua

I have been trying to help a dear friend find a son that he has never met. We have some few details and I have been able to dig for a few more.

What we know is that he was born June 1985 and his name is Joshua Gilbert Limasa and he was most likely born in California.

We are not 100% sure on the last name, we dont know if the birth mother hyphnated or if she only used one name.

At this point we are not even sure if my friend is even listed as the birth father!

My goal here is to find this Joshua and unite him with his father and three siblings and help end their long search for him.