Thanks @ Luke466
@ KolfMAKER
I ordered this replacement power supply: https://kosetrading.com/product/bang-olufsen-bo-beolab-8000-mk1-transformer-part-pcb-1-8006038/
It might work for now, but let me know if the RS trafo works for you. I might need to replace it at a later time.
Just wondering if the 15V is enough to power the system. Hope it works