Using Google Streetview, it appears to be a local authority (LA) estate, judging by the style of the houses and the uniform layout of the gardens.
Property maintenance would be carried out by LA contractors, who would be known, vetted and easily traceable. There are also privately owned properties nearby who would have their own tradesmen, not vetted and less traceable. And then there are the visitors to the estate and those just passing through the town.
Whilst the energy put into the local search parties is commendable, I think the perp will be long gone and the best clues will come from local people thinking back to who has been in their town recently.
Have they or their neighbours had any work done on their property?
Anyone been stopping off at the local shops recently?
Any construction work going on nearby, especially if it is reached by passing through the town?
Any work going on in Snowdonia? My partner was constucting a cycle path through the Trossachs in Scotland last year - we live 500 miles from there, but him and his crew drove up there in a number of vehicles. All strangers to the area.
Anyone who lives locally with a similar vehicle? I'll bet there are a lot
The list is probably endless, which is a depressing thought