It's well worth having a look yourself.
The 071 body is held on by 4 screws.Turn the loco upsidedown and locate the holes around the bogie area.The screws are recessed far in.When you get the screws out the centre part of the body lifts of.As you said some heat came from the top of the body,check the 21pin blanking plate and have a good look around with a bright light.Check with the loco on the track and see if there is a problem somewhere.
If the blanking plate is the problem,you should be able to get one somewhere.