Hello!
Disclaimer: I never owned an LS. Even if now, I would like to own one...
I've in front of me the original BMW Brochure for 1983 describing the R45, R65 and the R65 LS.
On the picture, the front cowl is mat. As the picture is taken, if it was shiny, it would have reflected the lighting like the red paint did.
But, on the other hand, I'm aware that BMW took pictures of bikes and accessories to put in the sales brochure and, actually, the production bike or accessories where different...
So who knows ?

Maybe someone having bought it's R65LS new can answer this properly.