Hello newbear and welcome to the forum.
Firstly regarding the Messner and Hagenmuller skins it doesn't matter whether they're alike or not as they're both stuffed mounts. That is skins stretched across a man made support, and we know for certain that the Messner specimen has been deliberately distorted to make it look bizarre. So when the people of the Himalayas last saw it it'd have looked nothing like it does now. In short it's little more than a hoax.
As for your other post, whether there's a good yeti or cryptozoology forum, this one is quite good but very quiet. On the rare occasions when it's busy it can be very good. There are a few regular posters each with very different perspectives but who are all very knowledgeable, not just about current events but also these stories' historical contexts. There are several such threads about Asian wildmen, the Almasty and a compendium thread on bigfoot.
Also the thylacine is pretty well covered.
Another good website is Cryptozoology.com , its tone is predominantly sceptical though. Like me.