It's just good old Halford's car primer white, nothing special but seems to work well. Covers and dries nice and smooth and hardly any loss of detail (it isn't too thick).
While this was drying I popped out and purchased the Vallejo paints that PSC recommended for doing the uniform, the main ones are:
• Helmet - Brown Violet 887
• Trousers - US Field Drab 873
• Jacket - Stone Grey 884
• Webbing - Buff 976
• Metal - Gunmetal Grey 863 (I've been using Tamiya acrylic gunmetal and it's horrible).
I've decided that I like Vallejo in comparison to the other acrylics I've tried - Tamiya, Revell and Humbrol. The are a consistency I like, the range is superb and the little bottles are really handy (and less messy).
As reference for how the colours might look I have turned once again to the Combat! TV series - this time the later episodes which were in COLOUR (1967)!*
* I was going to say that I don't remember this TV show being in colour - I seem to only remember it being in monochrome - but then I remembered that we only had a black & white telly until the late 1970s! I remember I threw a sicky from school the day the Radio Rentals guy brought our new colour TV (a 25" Bush). :)