I too remember the NHS Orange Juice, although I wasn't as struck on it. Liked malt extract, which was also given to mothers with small children. "Radio Malt" was the brand, IIRC.
When I was a lad my family certainly used Birds Custard powder (didn't everybody?) but few other convenience foods, except processed cheese like Dairylea and Primula.
But then my old dad got a job with messrs Birds Eye. I guess there was a staff discount, especially for new products, because he came home with all sorts of frozen convenience foods, and treats including the cream sponge cakes, arctic roll, eclairs, and mousse, as mentioned by others on this thread.
One of my favourite things was Birds Eye Chicken Rissoles. They had a particularly savoury yummy taste, quite addictive to a growing boy. Sadly they didn't sell them for long. After a while I guess they must have changed chicken suppliers, because the rissoles suddenly started to have bits of grit in them, and we realised that the magic ingredient was chicken gizzards. Nowadays of course "salade de gesiers" is a treat to be enjoyed on trips to France, but back then we viewed such offal with revulsion. Shame.
One of the odder frozen convenience foods was Instant Omelet, which was frozen beaten eggs in a carton. You thawed it out, shook the carton, poured the contents into a pre-heated greased pan, added the filling, et voila! An omelet in only twice the time, trouble, and expense of using fresh eggs.
