OK, this is my inspired guess on these things.
If all else fails and you decide to junk it, save the LCD display.
At a first quick look, it appears to have the standard interface for an LCD and can easily be driven by a PIC, if you get that far with PICs.
The RF module, takes the off-air signal and converts directly to base-band, ie audio and data for programme information.
The RF module will use a direct conversion technique to convert the RF (about 200Mhz) to baseband.
The chip which I have indicated as Baseband Signal Processing, looks a though it may have a Googleable part number.
My guess is that this chip splits out the audio and data.
Data goes to the microprocessor, audio to the audio amplifiers.
There will be control signals from the mirco to the RF Module.
These signals will select the frequency to which the radio is tuned.
All the above is based on inspire guesswork after Googling "DAB Radio Chipset", and finding the following useful information, as per the attachments
JimB