Having trouble finding a 2nd hand Doblo with all the rear seats in tact as they have mostly been removed for wheelchair access in WAV/Motability adaptations! If I bought one these WAV Doblos' is it possible to refit the back seats? ( Need to replace our lovely low mileage 02 diesel Doblo due to London ULEZ/congestion charge)

It is unlikely to be easy. The wheelchair vehicles have a central lowered floor, so that the wheelchair can be placed just behind the front seats. The floor across the car is no longer flat.
Have a browse through the pics here: https://www.secondhandwavs.co.uk/fi...ssible-vehicle-yw65fet-in-oxfordshire-6747860

I agree with Pb on this one. The wheel chair adapted cars usually have most of the original floor cut out and new fabricated floor put in. There can also be issues around different parts being used to rebuild the suspension to fit around the new floor, custom exhausts etc, which could make for some expensive repairs in the future as well.

Does it have to be or is there a specific reason for picking a Doblo? Generally they didn’t sell well and for ULEZ you’d need a post September 2015 model to be 100% sure it’s euro6
If you are set on a Fiat there is the Tipo estate or the 500L depending on use the 500x is also very good.

If you’re not set on fiat then there are plenty of alternatives to the doblo. One that sticks out in my mind and would save you quite a few quid over the doblo is a Dacia Logan probably 3-4K cheaper