Have you tried connecting the ariel to the digibox (Freeview box?) and then connect it to the TV. How is the reception now? If the reception is poor you might need to sort out this out first either get better digital ariel or booster first of all.

Then find out if it possible for the VCR to be connnected between Digibox and the TV so you have one scart for watching Freeview and record the programmes. In effect you are only using the digibox tuner. You are ignoring the tuners in the TV and VCR since the 5 analogue channels are duplicated in the Freeview anyway.

Then use the other scart for DVDP.