Extremely well said Ben!!! and TVV brings up very well placed observations as well
As collectors of authentic antique edged weapons, this is a subject that has always been with us, and one that has become increasingly disturbing as the prices gained by these weapons lure the opportunists. As collecting these weapons has increased in popularity, many with the resources simply will approach acquiring without abandon, leaving many serious students of these weapons behind. This is just one of the many factors that has created todays climate of incredibly priced antiques, fakes, authentically intended reproductions and the Frankenstein lot of conglomerations of components.
The dangers of this disturbing amalgam for the serious student of the history and development of weapons is of course that actual history that is held in the weapons themselves is often either completely destroyed, or misrepresented. Even the best intentions of cleaning up the actual weapons takes away all prospects of analyzing the age and original compliance of the components and reduces the weapon to the uncertainty of the world of fakes and reproductions. I would like to say here that serious reproductions are not 'fakes' but in many cases faithful reproductions, which I agree have merit in thier use for reenactment activities. These examples and activities are indeed viable for our study and understanding of the events in which the actual original weapons were used.I believe that the participants deserve considerable praise for the tenacity and resolve they exhibit in thier pursuit of the history and authenticity of the tactics, strategy and in our case, the appropriate use of the weapons.
One of the most confounding situations that complicates the often found 'hybrid' weapons is that many such weapons were in fact contrived during thier working lives, and are indeed authentic antiques in thier own right. Key examples of such weapons are often found in Spanish colonial forms, where frontier blacksmiths often fashioned ersatz weapons for the auxiliary units, using whatever surplus or resources were at hand. Many examples were refurbished in the field, and in the tribal regions of North Africa it is not unusual to see incongruous components together (as seen in the 'mixed up sword' thread). While these weapons due indeed have historic value, the problem is that the preying charlatans often 'create' such examples using parts from scrapped weapons and try to produce exotic pieces to tempt novice collectors. Take it from one who knows

...its a tough but convincing way to learn the difference.
Knowledge is power, and as always 'caveat emptor'!! Deal only with reputable dealers who will not misrepresent thier work, and will guarantee full refund if examination reveals problems. So called 'hybrids' are best acquired when they can be closely examined to verify telltale patination and various marks that reveal age of the work done.
All best regards,
Jim