Hello

I've read here that the oldest revision of Sound Canvas SC-55 are branded with a "GS STANDARD" logo.
Newer "GS" branded units have a different instrument map.
On the other hand, some games like Descent 2 and Duke Nukem 3D rely on the oldest units.
Here is my dilema:
I own a SC-55 with a"GS STANDARD" logo, but it is not working. It has a Control ROM v. 1.10, from what I can see on the ROM.
I own another SC-55 with a "GS" logo, but it is working. I don't know what ROM version it is, I can only assume it's 1.21.
I was wondering if replacing the "GS" unit ROM with the ROM from the "GS STANDARD" unit would downgrade it into a "GS STANDARD" unit.
Would that work, or are the different maps unrelated to the Control ROM?
Is there a way to test "GS STANDARD" specific instruments?

Thank you for your help!