another way do you know anybody that has trade plates, 
Trade Plates only cover Road Tax Licence (even then only under certain circumstances), if booked in for an Mot you cannot use Trade Plates for the purpose of No Tax to and from an Mot Station. you have to abide by the normal Rules and drive the Vehicle on its own plates.
As said before, if its a no Tax issue, and for 40 miles I would probably take the chance, as long as as the Vehicle is going to to be Taxed shortly afterwards for that period, probably wont hear any more about by post. Ive had to do it a few times as a Trader where Ive picked up a Vehicle that was on Disability Tax and can only be re taxed by Post or a DVLA Centre visit.
As for no Mot, yea, its a risky one, as Hotel21 says, potential uninsured Vehicle, if local, and Local for me would be 6 miles max, possibly up to to 10 miles if you live in the sticks, even then I would be paranoid about making sure everything is as legit as possible, ie carrying my Traders Policy, having roof of purchase, signed and time and date stamped and making sure the index plate was booked in for an Mot, even then I would only do this if I was sure the Vehicle was it in fit condition to drive and worthy of an Mot Test.
Having said all that, the Law states you can can legally drive an Untaxed Vehicle without an Mot, to and from a Local MOT Station as long as there is valid Insurance in place. There are no official distance or mileage guidelines as to what is local, but DLVA guidelines recommend it must be a direct route or maybe via a Petrol Station and the Vehicle cannot be on the road for more than 1 Hour each way in Total.
As for Al, I'm sure he already knows that Southend in Essex is a well known ANPR Monitored Ready Town, so he's knowledge will be his guide.