So, the RK11-C disk controller page over at gunkies says “no [indicator panel] inlay for such has even been sighted…”. But then over at bisavers, I see this:
http://bitsavers.trailing-edge.com/pdf/dec/pdp11/pictures/1120_RSTS-11/1120_RK_Panel_RSTS-11.jpg <http://bitsavers.trailing-edge.com/pdf/dec/pdp11/pictures/1120_RSTS-11/1120_RK_Panel_RSTS-11.jpg>
