That gunk is old shellac clear coat that has gone bad, usually caused by storage in a very hot gold place with lots of humidity. Heat is the worst. The black drips are a poor japan job by the maker. You can take the gunk off but you must be very carefull or you will loose what decals are left and scraping will take them off to. You can use denatured alcohol on a rag around a finger with a drop or two of linseed oil so you will not cut to deep into the decals. Once all is gone you will have to shellac the head using the french polish or you can use spray shellac(clear). Go to the tutorial section and look up my instructions to help you. Most of the decals on this machine are gone but try to save as much as you can. You have a hard to clean with this one.