I'm 100% the Sauer 202 is available left-handed in 300 Wby! (they've also just started doing it in 6.5/284).
The website ( www.sigsauer.de
) is closed for 'construction' at the moment but it gives some email addresses for technical questions -and these people actually answer email enquiries!
The frustrations I had finding a decent left-handed rifle (in a caliber I actually wanted) were enormous! The 202 has -for me at least- been an oasis in the desert.
I received my 300 Win Mag left-hander just before Christmas. It was 6 months from placing the order to receiving the rifle. (I also have a left-handed 202 in 308). Both my rifles have the Ilaflon finish (a rust proof teflon-like polymer), this is the same finish as on the Blaser rifles and I have found it really durable -OK not stainless, but rustproof.
The new rifle is a joy; it's the 'Alaska' model of the 202(In addition to being Ilafloned, the bolt is phosphatised. The stock is laminate.) On it, I've put: Warne Bases (all I could get to fit), Badger 34mm rings, S&B PM2 4-16x50. Very first group (using Norma Factory 180gr SP) at 100m was 0.53MOA (had to jump around a bit when that happened!) moved back to 200m 0.56MOA (more jumping) moved back to 300m 0.65MOA.
The 308 is more accurate than that! One of my pals has a 202 in 7 Rem Mag, that does better than 0.5MOA with Fed Prem Safari Trophy Bonded Bear Claw!
....perhaps I should change my logon name to Sauerfan!
Even though this still doesn't answer your original question, I hope it will be of help.