Proper leather shoes

Didn’t rapha used to do some?

Charles Tyrwhitt using some sort of discount code.

Actually from a quick google it looks like they're these which also get rebranded by others. I've got a branded and non-branded pair and like them.

Depending on how many pairs you are looking to buy, the below were the cheapest decent quality shoe trees I could find and there always seems to be a promo code kicking about.

https://www.bexley.com/catalog/product/view/id/21370/s/shoe-tree-red-cedar-00200d/