"worn 3 or 4 times" - because I got a new job and now work from home, so I rarely wear nice shoes anymore (very sad). PLUS, I own probably 50+ pairs of RL shoes.
"Do they run small or narrow?" - if you've ever owned, or tried on, any RL English bench-made loafers, they fit pretty consistently (at least to me), so that should give you a good idea of the fit. I also have a wide foot & I own probably 6-8 versions of the RL English bench-made loafers, so they've worked for me.
One note: the sole on the Marlow is a little bit thicker than the typical RL loafer and will take more time to break in (but will also last longer).
Let me know if you have any other questions….or if there might be any other specific RL English bench-made models you're looking for in 12D.
p.s. There's a guy in Brooklyn, NY that I sold about 10 clothing items to last winter. Met him thru eBay. I can PM you his contact info if you would like to get in touch him as a reference.