Repairing a Ringmodulator

Hi all,
Got some DIY gear build by Sam Zen. One of the things is a device with 6 ringmodulators.

And a picture of the insides:

It's based on TBA120s, ZM-FM amplifier with demodulator. It doesn't work yet, think I have to replace some components, especially the tantalum capacitors. Any suggestions?

Cheers,
Woody