Wrong sort of scabbard.

Highland/Scottish dress is not a uniform so I hesitate to say you shouldn't wear it but I cannot think of a way that you could short of wearing full levee dress without looking odd.

It might look quite good with a Jacobean shirt especially if you adapted the holster to contain a bottle opener or beer can holder.

I've been offered them before and have given it some serious thought but always drawn blank and not bought.

Sorry to be negative.