LeftyBassist.com

Anyone know where to get an Authentic Fender P Bass pickguard? Tortoise Shell color. Thx

Honestly, I would just go with Chandler pickguard heaven. I have a tort guard from them on my Jazz Deluxe, that I actually picked up from Southpaw guitar and it was way better than any Fender standard tort or the mint green guard that came with my bass. IMHO of course.

I ordered three of them for my red P Bass, one from Terrapin, one from Warmoth and one from Fenderparts.com (the one on the bass). The two first ones, I had to ask my tech to fit the heel. I think those aftermarket companies don't have the template correct. The one from Fenderparts is a badass Mintgreen distressed/60's vintage but I paid $100.
I can sell you the regular Mintgreen below for $20 + shipping if you want. It'll fit your bass perfectly as it is exactly the same one as mine. No Tort though. I think that Tort and Fiesta Red is awesome but Tort and Candy Apple Red is...

Do you have a picture you can post?

I have purchased several Fender Pick guards and I noticed that there is a difference between US/Mex and Jap basses as far as placement of the holes ect. I would suggest if you remove the pickguard and trace it out and send to them to confirm would save alot of trouble. Pickguard Heaven is great just make sure you note model, country and screw hold count.

Another option is to check out http://www.greasygroove.com/ they offer any model in Left Hand as well and will suggest you send them a trace.

I'll get you one soon, but it will be a few days since I am away from it and my photos.