Good analysis Pontius - but the problem of building military stuff for export is that you finish up subsidising the sales if you aren't carefull. Probably the last aircraft we exported in any numbers and didn't have to subsidise the buyer in some way was the Hunter.
By the late 50's the French, Russians and Yanks were all offering serious kit on deals that made the eyes water. We were never able to compete.
probably the worst cases of gold plating by British Industry were in naval vessels TBH - we used to sell a lot but as we increased the spec the costs went through the roof and, since hardly any potential buyer needed the capability, they went elsewhere