Good to see that the Blackbody was still around. Be careful if trying to clean the painted emission plate. The surface is easily damaged. I cannot be sure of a safe method of cleaning the emission plate as much depends upon the coating that has been applied and how solvents may affect it. Distilled water is the safest cleaning solution but IPA may be used on some other surfaces. LCD screen cleaner or water based glasses cleaner are also pretty safe cleaning solutions. Always test the cleaning solution with a cotton bud in the corner of the emission plate. If the white cotton bud soaked in the cleaning solution turns black when applied to ten emission plate, the cleaning solution is dissolving the coating !
Fraser