Thank you very much for the information Sir.The 5.6x35 is actually a European version of the old Winchester .22WCF cartridge...which the .22Hornet was derived from also.
There are a couple small dimensional differences between the 5.3x35 and the Hornet. Rim diameter and thickness.
The Hornet rim is roughly 0.010" thicker than the .22WCF/5.6x35R and 0.002"-0.003" larger in diameter, so most 5.6x35 chambers won't quite take an unmodified Hornet case. Otherwise, the cases are identical in dimension.
You can fit a Hornet case into the chamber but in a bolt action it causes extra strain on the extractor and in a break-action or falling block the rim will be just a hair too thick to allow the action to close smoothly.
I have seen several 5.6x35 rifles that have been modified to accept Hornet brass though since it's much easier to find here in the states.
Also, the 5.6x35 uses the old .22WCF/.22hornet bullet diameter of .223" instead of the more common, modern .224" size.
You can still get .223" diameter bullets as reloading components so this isn't a problem.
You can use .22Hornet dies to reload the 5.6x35.
I don't have any data for the 5.6x35, but from what I've heard it is loaded to pressures somewhere in between the .22WCF and the .22Hornet, so I wouldn't use max Hornet loads for the 5.6x35.
Back to the rifle itself...
They do show up every so often even up here in the backwoods of ND. A pair that were in very similar condition to your rifle (both traded in by the same guy) that came through our local shop and sold for around $400 about 10 years back.
I've seen much rougher ones at gun shows tagged for the same price in recent years but I don't know if they were selling at that price.
Looking at a few online auctions, similar condition to yours seems to be selling for around the same money yet with nicer condition ones going above $500.