Rogerio,
The boards can be removed then cleaned with Dawn, on a brush then rinsed off with water. Let dry long enough. The other parts can also be done the same way. The front and other metal parts can be cleaned with ammonia and a brush then rinsed. I suggest cleaning the knobs individually. IPA on a rag to get off any sticker residue and any other dirt that other cleaning did not remove. It will be tedious yet worth it. Oil the set screws and shafts of controls. The CRT can be removed and cleaned. The main board in the back, can be cleaned with a brush and Dawn or water, depending upon the dirt type. The removable sides and bottom can be cleaned with soap/ammonia and a brush. Use 91% IPA and a small brush to clean the legs/pins of the solid state devices while moving them up and down in their sockets right after applying the IPA. Clean all controls and switches with contact cleaner or IPA then exercise. You will be glad to take the time to clean it after you see it cleaned then working. I have had electronics that was filthy then after cleaning, looked excellent to new. I never regretted the time and effort in cleaning. I let dry in the sun all day, if warm/hot or over a heat register overnight when in winter. A fan will speed up the drying, then heat of some kind will do the rest while you are sleeping or at work for the day. Cleaned, there will not be an odour when turned on due to heat heating up the dust and debris.
Mark
