At €25 they are a bit expensive from Amiga Kit, but it's your money
The A520's are virtually indestructable and it WILL work on a non RGB SCART (with the cables and SCART dongle).
Does your TV only have one SCART socket?
I've never come across a TV manufactured in the last 10 years which didnt have at least 1 RGB compatible SCART socket.
Most Amiga SCART problems arise from incorrectly wired Amiga RGB cables rather than non RGB capable SCART sockets
The makers of the cables usually screw up the wiring to the FAST BLANKING (pin 16) on the SCART cable. This pin activates RGB mode on your TV.