The painting-out of Perspex panels apparently didn’t stop completely with the deletion of the fuselage windows in the JB serial number block of Lancasters.

This is a photograph of a piece of painted Perspex from a (then) new Lancaster from the PB serial number block; it is approximately 8.5mm / 0.33″ thick.

I’m not sure where this Perspex panel was on the aircraft but it is slightly curved; could it even be part of the H2S radome (which I think were made from painted Perspex)?