[Arran]

You mean shades of toner, there would be at least two, extra dark walnut and medium walnut, the grille area might be light walnut, buy dye based toner or it will obscure the grain too much. Blending a new finish with an old finish seldom works out well on the same panel, so at the very least you might want to strip and redo the front panel, the top and sides may be salvageable.
Regards
Arran