I never quite understand why some things are considered major alterations when there doesnt seems to be anything major about them.
Major Alteration:
An alteration not listed in the aircraft, aircraft engine, or propeller specifications, that:
1) Might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or
2) Is not done according to accepted practices or cannot be done by elementary operations.
Since it's already approved for the left wing, it's reasonable to state that it would not appreciably affect any of those items if also placed on both wings. The spar is not modified, leading edge carries no load, it's aerodynamic shape is preserved and the extra weight is minor in change.
The procedure to install can be done by accepted practices and elementary operations (metal cutting, riveting, wire terminals, electrical hook up, circuit protection)
I think it would be a major alteration if you wanted to add C195 retractable landing lights to the wings as they do affect flight characteristics. (which may help A models with thier little flaps

)