A5 Paperback covers for two books with two more to follow

I have already made a mock-up cover to serve as the e-book image for each book - I now need something similar to my mock-up but with a front/spine/rear. The stories feature a 1935 detective- and they require an image of Buckingham Palace and an image of the Duke Of York's Theatre with a silhouette of the detective (see attached files)