Way back when, I searched around for ways to increase height with some kind of leg extenders for a bench I had (that matched a sunburst brown Petrof upright I had, very pretty but impossible to match in a different bench).
Ultimately, I gave up because the things I was finding seemed like they would not be safe. Like the extenders used for beds would be at risk of a wobble when you move, and would be hard to deal with when moving the bench in and out from under the keyboard.
I ultimately settled on a thick towel folded carefully to add height that way. When I got my current piano, I then bought a cheap adjustable bench that was basically like throwing money in the toilet, and eventually a much better adjustable bench.
So, having said all that, two questions: 1) are you absolutely certain you can't find a bench with a satin finish that will match? And 2) do you really need the storage under the bench?
When I was bench shopping, there were lots of styles and finishes to choose from, including satin. And if you weren't concerned about the storage, you'd have even more options.
I recommend you take a look at the options sold from CPS Imports https://cpsimports.com
, and also Jansen Piano Benches: https://jansenpianobenches.com/
If you have the budget, consider a true Jansen Artist Bench. If you don't have the budget, the import options are quite nice. I ended up buying from Jansen Piano Benches bc CPS Imports was backed ordered. The one I got was an import, around $360?? I don't remember exactly at this point.
One last option would be to contact a furniture maker or woodworker and see what they could do for your current bench.