Daryl congrats on a great buy! It looks to me like a Suhl mauser, with the double set triggers, claw mounts and the stock design. Did it say any name on the barrel/action? They use to put the name of the specific rifle builder on the barrel.
Re the 65x57... it is to me one of the better 6.5 calibers! I have 2 rifle in this caliber. A Brno 21 and a Mannlicher. The Brno shoot sub moa with any bullets or powder combination from 123gr Lapua to 160gr RN hornady bullets! The MS I still have to load for. What make the 6.5x57 a better option for me, is the longer case! I can play around with seating depth and the magazine box is never a problem with longer bullets. I load mine to the same velocity as the 6.5x55 swede.
I dont know why the 6.5 creedmore is so popular??? To me there is better 6.5's that are over a 100years old!!
Currently I have the following:
6.5x54MS x 2
6.5x55 x1
6.5 x57 x2
264 Win mag (this is a beast)

I must say the InterSurplus website is amazing! Did you saw the Brno ZG47 in 8x64 Brenneke??
Can someone please buy that rifle!!