Few differences and a few example of ex-snipers and repro/clone snipers out there and for the lack of confusion – I am only going to discuss PU Snipers.
1. Un-Touched matching sniper - WWII original, as it came off the battle field. All parts original/matching. M52's would fall into this category. These rifles were selected for their accuracy, had nicer wood to metal fitting, had very smooth bolts/actions, lighter triggers and external surfaces had fine metal polishing vs rough ground surfaces. These are very hard to come by in the Canadian market and are quite expensive when found. Most common are M52’s.
2. Refurb’d WWII sniper - Made from a mix of WWII original and often some post war parts which are forced matched - but the receiver/barrel/scope/mount components are WWII. These refurbs were done in the 50/60's in Soviet arsenals with the purpose of being used as sniper rifles in a war than never happened. As these are forced matched, they will have many of the benefits of an original sniper, but may not have all the attributes of an Un-Touched example. There are a few Generations of these rifles (Gen 1 – No Import/Export markings, Gen2 – Molot markings under the handguard – some have US import markings, Gen3 – External Export markings on the receiver). Can currently be found for $600-750 (PS Militaria and select CT stores).
3. Ex-Sniper Restored or not - Many original WWII snipers were made into standard service rifles during the refurb process. These are often nicer than standard service rifles (smoother actions, metal finish, accuracy, etc.), these may be found in their 'new' service rifle state, or may be used as a base project for a restoration (original or reproduction bent bolt/scope/mount added). This restoration project would be completed recently (probably since 1990 – fall of the Soviet Union) and may have been done in Canada or overseas. Without optics these can be had for as low as $150, if you want optics and a bent bolt add $250-650
4. High Quality Reproduction/Clone - Generally done by a gunsmith or by an arsenal. PS use to carry examples finished in the Ukraine – I think they still have a few. These used better than average high wall service rifles, but they smoothed the actions and added high quality reproduction optics made in the Ukraine. Corwin Arms is doing something similar but they are often selecting ex-sniper rifles as their base product. $580-750
5. Do it yourself Reproduction/Clone - Pick a rifle any rifle (1943 Izzy High Wall is the best), get a mount/scope/bent bolt (original/repro) and do it yourself with a drill press - results are mixed. Cost $400+
The quality of reproduction optics/mounts vary extremely. I would stay with original mounts/optics if at all possible – as they are relatively common and not that expensive ($250-500 for an original mount/scope). I would recommend rifle #1 or #2 depending on your budget.