i contacted an acquaintance who's been collecting a very long time (40+ years) about this, and he wrote the following:
"Quite honestly, I can't see how this busby would not be original, and if parts were added, they certainly did a good job, and the additions are all of the period. The center of the feldzeichen is in blue (a bit faded, but blue) and none of the parts look like they were made any earlier than more than 100 years ago. The silver embroidery around the blue center most definitely is period. The fangschnurr is an officers' piece, and may be silver, instead of an enlisted colors (I am away right now and not near my research resources, so I don't know, off the top of my head.) The chinscales are correct for cavalry, and obviously of the period. The bandeau is the right one for that regiment, and I don't know of anyone reproducing them. The busby is an officers' headgear, so the interior would not have enlisted "leather fingers", and everything looks period. The only restoration or repair could be the stitching holding in the leather sweat band, but if it were, that would be inconsequential.
Looks like a really good price to me, and I wonder how high it will go."
for me, the part that really turned me off was the Totenkopf looked too small and the liner looked ... not german. But, who knows, maybe if it was a private purchase and consequently baerenfell instead of seal skin...
glad i passed on it, personally, but am not as sure its a bad copy as i was! :-k