June is great, but she’d need to be born then
I like Jane too
Estella is lovely - much nicer than Estelle
Matilda and Louisa are too popular to fit your brief, Amanda is nice but Mandy is awful - what about Miranda instead?
Louella rather than Louisa?
Marina or Maria rather than Matilda?
It’s a bit early to revive Lynne on its own, it still carries a downmarket 50s vibe - but maybe something like Rosalyn, Aislinn or Caitlin?
Elaine has the same dated low rent vibe as Lynne, plus there are millions of Eleanors and Ellies about. Martine also sounds tired.
I really like Laurence and Jonas
Antonio is a bit odd if you aren’t Italian - but you went for Anton you should also be able to avoid Tony.
Derek and Norman are terrible. If you want to revive mid century names - John, Robert (Robbie, Bobby), Richard, Michael, Adrian, Adam, Simon, Jonathan, Dominic are all nice. Peter is too, but it does tend to end up Pete.
Unique means one of a kind BTW, so it either means making something up, or at least picking something so obscure no one has been called it in years.