I don't think Koresh himself held a FFL, but one or more other Davidians may have. The BATF supposedly checked a few of the Davidians names for both machine gun licenses(tax stamps registrations) and FFLs, but not very many of them. Hard to see how they could have bought some of the stuff they bought from legitimate sources without one.
Of course the things that initially put the BATFers on to the BDs was a delivery of demilled grenade hulls, to be made into "complaint department, take a number" novelties for sale at gun shows and such. Anyone could order those, and have UPS deliver them, all completely legal, at least under federal and Texas law at the time.
An interesting journal article about the defective nature of the warrant is availble from the website of Dave Kopel. It appeared in the Hamline Journal of Public Law and Policy, and was coauthored by Paul Blackman. Kopel and Blackman are attorneys long active in the RKBA cause. The paper also reviews the Waco incident, dispelling some of the myths from both sides, including some inaccuracies from "Rules of Engagement".
If you have a particularly strong stomach, there's lots of documentation on the whole Waco affair, including pictures of melted children, available at the Waco Holocaust Electronic Museum
Thanks for the heads up.I been to the online museum.
It was clearly a watershed for YHvH given rights.
My first source was Waco: A Massacre and Its Aftermath