"new" 6.5x55...
Drewdoo 41--Money's tight, you want a 6.5x55. For heavens' sake don't bother re-barelling an existing rifle!! Haunt pawn shops and gun shops and gun shows in your area, until an already-Bubba-ized Swedish Mauser shows up. They come as a 6.5x55, and used, and Bubba-ized, it will cost mebbe $150-200 depending. (My most recent Swede was a pawn-shop rescue for $150.) The worse it looks the cheaper it'll be--but Bubba usually doesn't mess with the internals.
BTW, I like your choice. The 6.5x55 is light-recoiling, can be very accurate, and is deadly on Bambi--if YOU are deadly on Bambi. The cartridge is well up to the task--In Europe it is routinely used on what they call elk and what we would call a moose.
The days of getting a Swede Mauser as a milsurp, from one of the big mail-order houses, for cheap, are over, I'm afraid. But you don't want a pristine milsurp, anyway, you want a "project gun."
Have a gunsmith check it out for safety, and to be sure it hasn't been re-chambered by Bubba, and then have at it yourself. If you want a 'scope mount, you'll have to have the receiver drilled and tapped, and the bolt handle and safety modified--neither of these are terribly expensive, but have the 'smith do the D&T and the handle modification unless you yourself are an experienced welder/machinist.
The Swedish Mauser is sometimes called the 1896 Mauser. The Swedes changed the model number a couple times, but all the Swede Mausers have the 1896 action, so retro parts that fit that action will do for any Swede Mauser model.
My preference is a Boyd's stock
www.boydsgunstocks.com that you buy "unfinished"--Boyd-speak for not varnished--and glass-bed the action and varnish the stock yourself. Their catalogue doesn't specify Swede Mausers, although they do have several models for "small-ring Mausers," so I'd call 'em and ask--their 'phone people are very well used to talking people through to the correct choice. (605) 996-5011 is the number. They'll send you a catalogue for the asking. Nice people to do business with, and their stocks are nice, too.
BTW, Boyd's also has Bold triggers if you dislike the military 2-stage trigger--on a Swede, the trigger replacement is one pin push-out, remove old trigger, insert new trigger mechanism, and reinsert pin. Stupid easy. Me, I like the Timney trigger, having used them in several rifles. Brownell's has those.
www.brownells.com It installs the same as a Bold, in a Swede.
You can do this project in stages, which makes affording it much easier--Step 1 is simply to buy the rifle and have it √ed by a 'smith. If it's shootable as is, there you are. Then you and your pocketbook decide what and how much for Step 2, and so on. You can work on the thing for years, if you're so inclined.
Best of luck on the project, again, nice choice of cartridge, and PLEASE keep us posted, with pix, as you proceed through this!
ETA--The Timney Trigger I installed in my Swede Mauser did need a little modifying to fit the receiver--a bit of grinding with a dremel or similar tool did the job just fine. Note: I did NOT grind on any of the sear areas!! The Bubba stock needed some relief grinding also, to allow the Timney in. All this grinding and sanding took something less than an hour of time doing it carefully. First time for me that a Timney hasn't been a drop-in fit, but certainly no big deal.
Long's I'm adding stuff: Yeah, being a lefty with a righty bolt action sucks. Agree with the posters who say get a Rem 700 that's already a lefty. The Rem 700 has more retro parts available for it than just about anything else, barring the Ruger 10/22 and the AR-15. You MIGHT find a lefty 700 already barrelled for the 6.5x55, but I wouldn't bet on it. The lefty 700 is of course going to cost a lot more than a milsurp. Keep an eye out for one in ANY relatively light-recoiling cartridge, then use that "as-is" until more $$ is accumulated. Good hunting.