Hi,
Great if you know it is restored back to full working order. In normal operating conditions (not left in some damp basement or hot attic) the turntable should not require anything more that being kept clean and dust free. As I said before they are built like tanks. Depending on how clean your vinyl collection is you will want to occasionally clean the stylus tip. I use a small piece of Magic Eraser, place it under the cartridge (when the turntable is off), then gently push the tonearm (with cartridge) straight down onto the piece of Magic Eraser. Then release the tonearm so it goes back up. That will keep the stylus tip clean of debris it picked up in the record grooves.
Any phonograph requires an RIAA preamp to play. All amplifiers back in the day of turntables included the RIAA phono preamp. A small number of turntables included a built-in RIAA preamp. The Beogram 4004 was not one of those. Modern amplifiers typically only support CD/DVD line level source inputs and have no phono preamp support. There are a number of standalone RIAA phono preamps available now from solid state to tubes (in all different price ranges) that will decode the RIAA signal coming from the phono cartridge and prepare the audio signal for the modern amplifier source inputs.
I am strictly a vintage audio person so I can't really advise you on powered speakers. However those devices handle inputs from CD/DVD devices is how you would connect your phono preamp output to the powered speakers. There are plenty of others here on the Beoworld Forum that can advise you on that...including Steve at Sounds Heavenly. That should be right up his alley.
-sonavor