I've been scrounging gunshows looking for bubba'd 1917 actions to build a big bore rifle from, and there are still some affordable projects out there. But like mentioned ealier, don't mess up a nice original one, they are just too hard to find complete anymore for less than stupid expensive... I know where there is an original complete 1917 eddystone with a decent stock and an ugly bore, still thinking of buying it to see if it cleans up ok and avoid bubba getting another one... But by all means find a butchered one and build a custom out of it! They are really strong actions, they weigh a ton, but shoot so nice because of it. I've had several, and I plan to have several more before I'm done...
Adcoch, you can buy new mil-spec barrels from Criterion that probably outperform the original for around two hundred (after you shoot it first of course because some ugly bores shoot quite well--they just foul quickly and are a bear to clean.) These new barrels are timed properly and have all of the necessary milling done apart from finish reaming (they are short chambered barrels) and qualify for CMP matches. I believe that you can even get a m1917 barrel in .308 from them course not to compete with. Major issue is that you may have to mill a groove at the existing barrel shoulder to get it unscrewed and removed--Eddystones have a reputation for being exceptionally tight and you can crack a receiver easily with the amount of torque necessary to remove the barrel.
O/P--some good unfinished 1917 Herter brand Monte Carlo style sporter stocks including a LH one on Fleabay right now if that is what you want for not a whole lot of money. You would need to do the final inletting, sanding and finishing. Also try looking up Bob's Gun Parts in Royal, Arkansas who also has a bunch of old sporter stocks for mil-surps.
A tip for Fleabay and Gunbroker searches is to use several search terms--e.g. the m1917 rifle is referred to as American Enfield, Eddystone, 1917 Winchester, 1917 Remington, sometimes mistakenly as just Enfield, the 1917 rifle, and so on. Fleabay will suggest additional search terms at the top below the search box. Occasionally, it pays to search generic terms such as vintage rifle stocks--if you search all of them one time, then all you have to do is search the most recent listings (an option of Ebay not Gunbroker).
Gunbroker has recently mangled its search capabilities in the last month and generates a lot of false positives with many not having any relationship with the original search term. I suspect that part of the reason is those hideous ads that they insert into each search results page. More pages, more ad hits. The search function is better than it was several weeks ago but far from what it was even two months ago. Even there, use multiple search terms--e.g. I am looking for parts on a specific Finnish Mosin--search terms would be Finnish Mosin, Finnish Mosin Nagant, Finnish m27, Mosin m27, and if no hits, try simply Mosin Nagant. Often the best deals can be when the seller doesn't use the right keywords or misspells them--e.g. Craig stock instead of Krag etc.