One book is Anthony Vanderlinden's Belgian Browning Pistols, which covers the wartime BHP pretty well.
FWIW, I advise caution in firing those wartime guns. They are not going to "blow up", but Belgian sabotage took the form of spoiling steel or "forgetting" things like heat treatment. I have seen a couple that had slides and barrels in about the same Rockwell C range as Camembert. A few shots about wiped the top half of the locking lugs and hung up the gun.
(Oh, and how about toning down the size and color on your posts? I promise we will know you are here without that.)
Jim
