Who is the taxidermist? And please post pics to back up what you are saying.
As to size, we measure nose to base of tail, not head to hind foot, but a bear over 700 pounds is probably in the 80"+ nose to butt with a belly at least 60" around the middle. There ARE black bear forms in this size, anything bigger requires making those forms bigger or just altering a big grizzly/brown bear form. There is no excuse for any taxidermist to not be able to alter a form to make it bigger. Long blade reciprocating saw, lots of 2 part taxidermy urethane foam, and threaded rods run through to add stability.
As to the skull, how does one drop a huge bear skull when it's raw and break it? If it was already cleaned, it would still have to hit a hard floor with alot of force to really mess it up - and the broken sections got lost? Was he playing baseball with it and it was being used as the baseball?
Now if you shot it in the head, that would cause damage depending on caliber and load, but you can make sure to clean it and save every broken bit and glue it back together. The gluing may still disqualify it from the official record book, but you will get very accurate measurements if it is put back together right. Did you shoot it in the head?