actually!
(and I’m really sorry if you knew this already and were being sarcastic I am very bad at reading these things-)
there is a fairly high chance Clara actually was named after Lee Harvey Oswald. Oswald shot Kennedy on 22 November, 1963…
…and the next day, as the world was still reeling, An Unearthly Child aired. In the wake of the news, viewership was so low they actually had to air it again.
So Clara’s name may not be a tribute to Oswald, but…I’d be really surprised if that’s not where the name comes from.