I actually have a fantasy rough draft set in a (I guess) Victorian-esque era where I did first-person retrospective. I found it great fun, until I couldn’t figure out how the darn thing would end. (but I haven’t given up on it!)
I recommend reading Treasure Island by Robert Louis Stevenson (which employs a First-person retrospective narrative) and books by Charles Dickens or other Victorian-era authors to help get a similar prose which might help with the old-fashioned feel if you want to (note: it takes a while for Dickens novels to build up, it’s a slow burn and the final chapters are so hard to put down once you’ve become so invested A Christmas Carol is pretty much the only one I can think of that I’ve read that you don’t necessarily have to work for).
I think maybe including how your character feels about the events as they happen may breach the distance a little, as well as suspense and maybe even a character who doesn’t remember everything that happened or learns of events afterward?
Also, I recommend David <i>Copperfield</i> by Charles dickens, it’s in the first-person retrospective as well as being one of the first Victorian novels I remember listening to on audiobook.
I hope this helps you 😊! (I am in no way an expert on this narrative style, I just thought I’d share what I know — and there’s nothing that can’t be fixed in the editing stage!)
We crazy people are the normal ones.