you mean you used GW Purity Seal varnish ( which is more a satin finish than matt)
The cloudy , not perfectly clear finish you are getting here is usually caused by moisture in the air ... which is water reacting with the varnish .
Were the models left somewhere cold overnight ??? There may have been some condensation on them , enough to cause this . Did you leave them where there is moisture, such as where the washing machine is ???
There may be little you can do ... but if there is not too much opaqueness, i would suggest getting some GW Ard coat gloss varnish and give the models an nice even coat all over with that, or just on the brassy colour areas might give a good effect.
must be a right bummer all the same
