I don't know how useful this will be on a ship site, with auxillary aircraft and armor, but it's a good tip anyway...
When you want frosted clear, one of the usual techniques is to sand it. Works, but is always risky (the coarse layer could be too course and leave gouges).
A very easy, fast, and simple method is to use DullCote (any dull sealer). It turns the clear plastic to a uniform frosting.
(My mate at
Paragrafix just used this on the Dr Who Tardis 1/6th scale kit and it works great). Like I say, not sure who needs to frost clear, but next time I do, I will not sand!