They look close to these but not quite. Have you tried polishing the chrome part?

https://www.westmarine.com/uflex-usa-two-lever-top-mount-control-straight-levers-15698665.html

 

They look a lot like that, quite possibly even the same brand. Mine have raked handles but I see that on WM too. They're not quite right (one lever is shift, one is throttle and I need two separate dual lever controls, shift on one bank and throttle on the other) but it's a great start. Thank you. Having them pop up on West Marine suggests I didn't look very hard but I promise I did.

The pitting is awful. I've tried some Flitz but no good. I'm happy to work at them if I knew what to try. I think it's a plating that's come off rather than surface corrosion. I'll have to take some better pictures.