If you love the Leopold, why not get another Leopold (the FC900R comes in a version with top or front printed PBT keycaps that are very nice).
If the WASD weren't acting up, I'd recommend getting a nice set of doubleshot caps for it, so the legends will never wear out and they improve the feel of a board.
I know these aren't White on Black, but they're very smart and businesslike and if the colourway appeals to you, they're really top quality caps:
https://www.massdrop.com/buy/originative-gmk-dolchThick doubleshot keycaps in Cherry profile made by GMK, with a consistent underside gap which suits thin orings. Your fingers will appreciate them
Or if you don't mind getting just a little more colour in your life, there's SkiData+, also going to be made by GMK:
https://geekhack.org/index.php?topic=74079.0