Improved flamer used to be a great weapon to level up BG'ers efficiently and cheaply.
That was until some Darwin award nominee, admired by god and all for great achievements like making cripplers useless, 0-cap economy financing system, critburst 280+ hp tanks, super sledge blueprints and uncraftable brotherhood armors and known for suffering from severe grinding autism and spastic nerdism in personal life, decided it would be great to remove it from the default crafting table and make its blueprint a super rare item, third only to CA and plastics (and the much-appraised super sledge and super stimpak bps ofc !).
Thus he became very rich and even more famous, gaining him reputation, loot and booty all over the world.
...........
Anyway, don't except a Dev to tell you the chance to find one. You may chose one of the following FGA (Frequently-Given-Answers) instead : "I don't know","Find it out for yourself", "Wasteland is harsh" and the most popular "Soon".