AFAIK, the FN BHP did not use a cast frame; they were forged. I don't know about the various clones, except the FEG which also appears to be forged.
This is not true. There are many FN Hi Powers that have cast frames. They still make them and sell them to the rest of the world. In the early 2000s there are SFS guns and a large amount of standard MKIIIs imported by FN that were marked with import marks Coulmbia, SC & Fredericksburg, VA. They attempted to attract the LEO market and failed. These guns were dumped to CDNN and sold for about $400-$500 a piece. I should have bought 50.
If you look at the Israeli imports you will find MKIII guns with FN rollmarks. AIM has some right now. http://www.aimsurplus.com/product.aspx?item=F1FNHPMK3I