Baydog id right about the degreasing, or lack thereof, on the Kudu skull.
The broken nasal bones and broken impala skull look like shipping damage. This may be due to improper packing or improper re-packing by inspectors while in transit. My Warthog and impala skulls had been removed from the bubble wrap and simply placed back in unprotected, fortunately they were not damaged.
My suggestion for the Kudu is to remove it from the plaque and soak it overnight in laquer thinner (skull portion only) and then soak it in a sloution of Dawn dishsoap and water (Dawn for some reason is a far better degreaser than other brands).
The Impala can still be saved by getting a local taxi to trim it up to a european half skull mount and re-attaching it to the plaque.
I am not sure what the tail has in it but I found when re-hydrating my African skins that they were extremely dirty as well, they looked clean but the re-hydrating solution pulled alot of dirt out of them. It is possible that they tumble them in some type of clay to condition the hair and hide post-tanning instead of the sawdust used over here, I dont know that for certain but it does appear that way to me. I would try simply brushing it out and if that fails try washing it by hand and brushing it out. The stiffness is probably due to a lack of staking and oiling of that area. My flat Wildebeest tail was the same way. Take it to a local tannery and they should be able to soak it down, stake it and apply the proper water based tanning oil to soften it up nicely. despite their hard dried outward appearance my African tanned hides were actually nicely tanned, simply under oiled which is not really a big deal.
Your horn hole pics are too fuzzy to see anything but simply by the position I would say they are, as stated, drilled to keep the horns together and attach a tag. I would much rather have a hole in MY horns than someone elses undrilled horns. You have to remember they do not boil skulls 1 at a time and it would be impossible to match up horns and skulls without this. Having said that it is still a pain. I have a couple here to fix and will photograph the simple process I use and you will see they can be sone invisibly if done properly. For now here is a link to a Taxinet thread on fixing antlers and horns so you can get an idea of what is possible.
Taxidermy.Net Forum - Busted! Antler and Horn Repair,Updated
Look at all pages as there have been more repiars added as time went on.
