OK - response to various points. Populations of pedigree Tamworths in US and Canada are minute and make no difference to the world population of TWs which is rare. The Saddleback populations in Australia and USA are even smaller and again make no difference to the world population of the breed. Hampshires however are widespread throughout the Americas and are thus not endangered. The fact that there is a small population here (but much larger than TW and BS populations overseas) is thus irrelevant to the overall situation. To extrapolate your logic further, i.e. because there aren't many of these American pigs here in the UK they must be rare, do you consider because there are hardly any Large Whites in Scotland that they too must be rare?
Just because something appears on the BPA website doesn't make it true.
Mangalitzas. There is no truth in the assertions by some that Mangalitzas are related to Lincolnshire Curly Coats. It is a story concocted by those who imported them to make their stocks saleable to others in the UK. Yes, a small number of LCCs were exported to eastern Europe in the 1950s - too few to have made any difference wahtsoever. Further, no one can point to a single pedigree and show any direct lineage to a single LCC. Managalitzas are widespread throughout Poland, Hungary, Austria, Slovakia, Czech Republic, Albania etc. and again the world population is enormous. Mangalitzas had a curly coat even before LCCs were exported and the only relationship between them is that they share a rogue gene that causes the woolly appearance. BPA are a commercial organisation and open their business to any foreign breed that happens to be imported to the UK if so requested. Kune Kunes decided to do their own pedigree recording. I attach a photo of Mangalitzas from the beginning of the 20th c.