I'm looking for historical romances where siblings/friends/whoever switch places.

For example: The Husband Trap by Tracy Anne Warren has the sisters switch places to marry, and One Kiss From You by Christina Dodd has cousins switching places.

So the story is like so. Any recommendations?

Hm, yes. Lol, I need to check for the author, I've read so many I can't remember names or titles so...

The Switch by Lynsay Sands. Loved it, it was hilarious.

While taking turns masquerading as a man with her twin sister, a young noblewoman learns the true joy of being a woman when she falls head over heels--and out of a window--for Lord Radcliffe.

So you see how it's hilarious that Lord Radcliff is attracted one moment to a lady and the next to a young 'gentleman'.

I have (had, hope I haven't deleted it) a folder on external harddrive that has 'switch places' books on it. I'll get back to you on that.

This topic reminds me of Diana Gabaldon's Outlander series

the family by Mario Puzo

Have you tried Anne Gracie: The Merridow Sisters: The perfect Kiss. No 4 in the series.
To rescue her friend...

Grace Merridew's childhood has made it hard for her to trust men and in three years on the marriage market, her senses have never been stirred. So she makes plans for a life of adventure instead—to see the moon rise over the pyramids of Egypt and dance amid the marble ruins of Greece. But first she has to help a friend.

She must enter the lair of the Wolfe.

Grace's timid friend is being forced to marry Dominic Wolfe, who stands to inherit a huge estate if he weds. The Wolfes have a terrible reputation, and if there's one thing Grace cannot stand, it's a bully. Her friend begs for help to escape this marriage, so Grace acts as the plain and mousy chaperone on their visit to the groom-to-be. But when they arrive, nothing is as they expect, and Grace is scandalized to find herself being pursued by a big, bad Wolfe with dishonorable intentions

False colors by Georgette Heyer.