As a belated final thought, I found these helicopters in one of the local discount shops. At 99p each they're almost the exact correct scale for my Action Force project.
This red helicopter is a good size for landing an SAS raiding party.
The Red Shadows were sometimes depicted with Russian Mil MI 24 Hind A gunships in the comics. This certainly isn't a Hind but it will stand in OK and shares the 2-part windscreen.
The searchlight under the front will be cut off and replaced witha ball-mount chin gun made from a plastic BB pellet and a bit of brass wire.
For Z Force I've got some slightly heavier helicopters than the SAS choppers.
These have some nice details moulded into the windscreen as well.
I've got enough to airlift in most of my Z Force and Red Shadows. There are only 2 helicopters for SAS Force but they're not likely to need such a large capacity for airlift anyway.
These will obviously all need a new paint job!