I am not an expert on K98 sniper rifles, but I've read about 80 to 90% of what one sees for sale is a put together rifle, and very few originals exist in the USA. I have two good books of these rifles, Peter Sencih's book, and Richard Law's book on K98 snipers.
The rifle pictured is the final form of the short side mount with the unique vertical locking lever (circa late 1943 - in 1944 they adopted the long side mount). It is believed that final short side version was invented by the Saur firm in 1943. (Source: Sniper Variations of the German K98k Rifle, by Richard D. Law (page 30).
I would want to see a 'ce 43' or possibly 'byf 43' as the base K98 rifle. The mount should have a serial number that matches the rifle and scope if original, although even in Law's book his example does not have a matching set-up. Scopes associated with that mount are 4x Dialytan and 4x Kahles. I think the best advice I read re German K98 snipers is do not pay a lot for one unless examined by a true K98 expert, as again, most are either fake snipers or a post-war put together based on whatever optics and mounts could be acquired.
That said, I have read one except of a 6x scope being used by a famous German sniper, but I don't know the details. He, like many snipers, had his rifle immediately destroyed when he heard that Germany had surrendered. He had it run over with half-track, as any German solider getting caught with a sniper rifle in May 1945 would likely be executed on the spot by the Russians, and I doubt American soldiers would show a lot of mercy either if they came upon a German soldier with a sniper rifle....